Theresa May has told top City executives they should "emphasise the benefits for Europe" of a Brexit trade deal that includes London's financial centre.
Downing Street released a statement after the PM and Chancellor Philip Hammond held talks with senior bosses of top institutions including Barclays (LSE: BARC.L - news) , Goldman Sachs (NYSE: GS-PB - news) , Lloyd's of London and Aviva (Amsterdam: AW8.AS - news) - a meeting first reported by Sky News.
It suggested the Government - and the executives present - were in agreement that Europe as a whole would lose out to other financial centres in the world - such as New York or Hong Kong - through a 'no deal' scenario for the City.
The talks took place at a time when many big names remain under pressure to relocate staff to EU centres to ensure they maintain rights to operate in nations regulated by Brussels.
The statement on behalf of the PM said there were additional calls for clarity on the future - with a transition deal yet to be formally agreed.
A spokesperson said: "The Prime Minister gave an overview of the UK's position and updated on Brexit negotiations - including the UK's aim to agree an implementation period by the end of March.
"The Chancellor emphasised the need to make the interests of consumers and taxpayers central to the future regulatory relationship between the UK and EU.
"The business leaders were united in emphasising the need for as much certainty as possible. The conclusion of phase one talks were deemed to have provided reassurance and the business leaders gave their views on how to maximise the benefits of an implementation period.
"The Chancellor said that the UK's financial services sector was an enabler of the real economy across Europe and that any moves to undermine it risked undermining Europe's economies. There was agreement that fragmentation of the European market would likely benefit centres outside of Europe.
"In her closing comments the Prime Minister asked that in their conversations in European capitals, the attendees emphasise the benefits for Europe as a whole of the UK's financial centre."
:: Hammond seeks clarity from EU leaders on future relationship
The meeting took place against a backdrop of lobbying by the Government aimed at pushing European capitals towards a Brexit trade deal that works in both the EU27 and the UK's interests.
Ministers rounded on the Labour Mayor of London, Sadiq Khan, earlier on Thursday after he released the findings of a study he commissioned relating to the impact of various Brexit scenarios.
It warned of a potential £54bn hit to the economy by 2030, with 500,000 jobs lost, if the country were to divorce Brussels with no trade agreement in place.