Some are demanding that the Government publishes a proper cost/benefit analysis with the criteria and thresholds used to trigger the key tiering decisions.
Eighteen boroughs, more than half of London, are now seeing falls in confirmed cases in the week to November 19, according to official figures.
Infection rates are also heading towards Tier 1-type levels in a swathe of central London which is so economically crucial for Britain.
The second wave epidemic appears increasingly likely to have peaked in the capital around 11 days ago, the case data suggests.
Amid fears that the Government could nevertheless plunge the capital into Tier 3, Tory MPs and Mayor Sadiq Khan lined up to oppose the move and the Prime Minister may have to rely on Labour votes to get his plans through the Commons.
They believe Tier 3 is unnecessary to fight Covid-19 in London, would cause huge harm to the capital’s businesses.
Latest figures showed the seven-day rate of new cases per 100,000 in the capital falling to 187.4 on November 19, the fifth day of decline since a possible peak in the second wave on November 14 of 199.4.
In Westminster, cases are down 19 per cent on the previous week to a rate of 127, in Southwark ten per cent to a rate of 109.8, Camden 23.2 per cent to 104.1, and Kensington & Chelsea 11.7 per cent to 130.7.
A rate of 100 was one of the triggers for previously moving areas from Tier 1 to Tier 2, and health chiefs told MPs that the threshold may now be 120.
Without knowing what thresholds the Government is applying there can be no proper scrutiny by MPs, the public or local council leaders as to the decision making process that informs the Government’s choice to move us into Tier 1, 2 or 3. Many MPs are demanding for this clarity in time for the looming Commons vote to approve new Covid-19 measures.
Ministers have so far rejected calls for borough-by-borough tier levels which MPs are advocating given the huge variations across the capital.
But the Government faces huge opposition to dumping London in Tier 3 after lockdown ends on December 2, including from many Conservative MPs and business chiefs, even if the restrictions are reviewed after two weeks.
Harrow East Tory MP Bob Blackman said: “We better not be in Tier 3 otherwise it is all but over for Christmas for the hospitality sector. London’s economy would be decimated. A review in mid-December would be far too late.”
In Tier 3, pubs and restaurants will be restricted to deliveries and takeaways only. Indoor entertainment venues will also remain shut.
Orpington MP Gareth Bacon said: “The data we have at the moment does not support Tier 3 and does not support a pan-London approach.”
David Simmonds, MP for Ruislip, Northwood and Pinner, said: “Given the relatively low prevalence in London and high compliance, I believe no higher than Tier 2 is appropriate for our city.”
Hendon MP Matthew Offord said: “Many parts of London do not have numbers of coronavirus cases that would justify putting the whole capital into Tier 3.”
Nickie Aiken, MP for the Cities of London and Westminster, said: “I would be extremely disappointed if London is put into Tier 3.
“The near Herculean efforts many restaurants, cafes, casinos and cafes etc have put in place to make their premises Covid secure should be recognised.
“I have seen no data to date to provide the evidence that the capital should enter Tier 3 rather than 2.”
The Government has laid out a series of health criteria for deciding tier levels including cases rates, across the age groups and for the over 60s, how quickly cases are rising or falling, positive test rates and pressure on the NHS.
But they have not given economic criteria on the damage to businesses and jobs, or the exact benchmarks to judge the health criteria.
On the possibility of Tier 3 being imposed on the capital, as happened to northern cities, former Tory leader Iain Duncan Smith, MP for Chingford and Woodford Green, said: “This looks like a political gesture to placate other areas. There is no reason to be moved from 2 to 3, and they should now publish the cost/benefit analysis on such action.”
Health Secretary Matt Hancock insisted on Tuesday that it would be “unreasonable” to set fixed thresholds to decide which areas fall into the new tiers.
He told MPs: “We’ve set out the five indicators that we will look at, but we can’t credibly put a set of statistics on those, because when you’re looking at five different measures, then you’ve got to take into account the basket.”
However, Romford MP Andrew Rosindell said: “I am against going into any tier! The only tears I see on the horizon will be jobs destroyed, businesses closing, homes lost, poverty, unemployment and people suffering from mental health issues on a massive scale.”
Beckenham MP Bob Stewart said: “I don’t think London deserve it (Tier 3). It would destroy our businesses.”
Sir Bob Neill, MP for Bromley and Chislehurst, Wimbledon MP Stephen Hammond and Kensington MP Felicity Buchan have also voiced their opposition to the city being put into Tier 3.
Downing Street says no decision has been taken on the tiering, with key meetings due to take place today and tomorrow.
Ministers may be tempted to seek to drive case numbers down hard in anticipation of a rise at Christmas where three households will be allowed to meet for up to five days, a controversial decision if it means extended periods of tighter restrictions.
Health chiefs also believe the measures in Tier 2, introduced in the capital in mid-October, had flatten the rise in cases and they may have been falling.
The new Tier 2 restrictions are tighter than the previous ones.
Labour MPs and the Mayor of London Sadiq Khan are also warning against a move into Tier 3 or called for the lowest tier possible.
Writing in The Standard, Mr Khan said: “I firmly believe that it would be right and sensible for London to move into Tier 2 restrictions when the national lockdown is lifted next week - anything else simply wouldn’t make sense.”
Ealing Central and Acton Labour MP Rupa Huq said: “It would be ludicrous to punish us by putting us in anything higher than Tier 2.”
Mitcham and Morden Labour MP Siobhain McDonagh stressed local hospitals were coping and opposed Tier 3, saying: “It makes absolutely no sense, our hospitals are performing really well.”
Ilford North Labour MP Wes Streeting said: “We are not out of the woods yet, but there are signs that the hard work of Londoners is paying off. That would seem to point to Tier 2 restrictions for London.”
Hackney South and Shoreditch Labour MP Meg Hillier added: “I am backing the call to go to Tier 2 - current infection rate is heading in the right direction and support for businesses is vital and if Londoners carry on carefully we can save lives and protect business.”
Putney Labour MP Fleur Anderson said: “After lockdown ends next week an evidence-based decision must be taken to place London in the lowest possible tier.
“Businesses in my constituency are fighting for their survival, particularly those in the events and hospitality industry.”
Liberal Democrat leader Sir Ed Davey, MP for Kingston and Surbiton, demanded that the Government give more details of how it is making the tiering decisions.
He said: “If the scientific evidence is that to keep people safe we must enter Tier 3 lockdown then Liberal Democrats will support it.
“But it is high time the Government hold up their side of the bargain - to get Londoners to comply they must explain what level of infection warrants Tier 3 and what level of infection will mean we can go down to Tier 2.”
Latest figures showed in Wandsworth a total of 445 new cases in the week to November 19, down 159 (26.3 per cent) on the previous week, and a seven-day rate per 100,000 of 135, in Camden 281 cases, down 85 (23.2 per cent) with a rate of 104.1, Islington 337, down 88 (-20.7 per cent) with a rate of 139, Westminster 332, down 78 (19 per cent) with a rate of 127, Richmond 220, down 40 (15.4 per cent) with a rate of 111.1, Waltham Forest 537 down 97 (15.3 per cent) with a rate of 193.9, Sutton 320, down 48 (13 per cent) with a rate of 155.1, Barnet 665, down 92 (12.2 per cent) with a rate of 168, and Lambeth 464, down 67 (12.6 per cent) with a rate of 142.3.
Kensington & Chelsea saw 204 cases, down 27 (11.7 per cent) with a rate of 130.7, Kingston 298, down 37 (11 per cent) with a rate of 167.9, Southwark 350, down 39 (10 per cent) with a rate of 109.8, Ealing 772, down 85 (9.9 per cent) with a rate of 225.9, Hillingdon 640, down 69 (9.7 per cent) with a rate of 208.6, Tower Hamlets 785, down 61 (7.2 per cent) with a rate of 241.7, Hammersmith and Fulham 339, down 24 (6.6 per cent), with a rate of 183.1, Bexley 637, down 39 (5.8 per cent) with a rate of 256.6, and Haringey 377, down 18 (4.6 per cent) with a rate of 140.3.
Brent has seen no change on 688 cases and a rate of 208.6.
But 13 boroughs are still seeing rises, though many smaller than previously.
Merton saw 403 cases, up 86 (27.1 per cent) and a rate of 195.1, Havering 1006, up 173 (20.8 per cent) and a rate of 387.6, Greenwich 570, up 94 (19.7 per cent) and a rate of 198, Bromley 547, up 77 (16.4 per cent) and a rate of 164.6, Redbridge 924, up 123 (15.4 per cent) and a rate of 302.7 and Enfield 739, up 95 (14.8 per cent) and a rate of 221.4.
Newham saw 804 cases. up 95 (13.4 per cent) and a rate of 227.7, Croydon 644, up 70 (12.2 per cent) and a rate of 166.5, Hounslow 566, up 44 (8.4 per cent) and a rate of 208.5, Hackney and City of London 500, up 30 (6.4 per cent) and a rate of 171.9, Barking and Dagenham 556, up 31 (5.9 per cent) and a rate of 261.1, Lewisham 378, up 15 (4.1 per cent) and a rate of 123.6, and Harrow 471, up two (0.4 per cent) and a rate of 187.5.