Theresa May has insisted she is committed to protecting the dignity of Britain's elderly as her plans to cut pensioner benefits and overhaul social care funding came under fire.
Labour leader Jeremy Corbyn warned deaths from hypothermia would increase as a result of Tory electionproposals to withdraw the winter fuel allowance from better off pensioners.
And senior Conservative Sarah Wollaston said scrapping the planned cap on care costs would leave people facing a "miserable lottery" when it came to funding their future care needs.
To compound Mrs May's difficulties it emerged pensioners in Scotland would escape the means-testing for the winter fuel allowance – worth up to £300.
The Scottish Conservatives' manifesto said devolution allowed them to make "different choices" on social security matters and that the allowance would be protected for all older people.
Scottish Secretary David Mundell told The Herald that the decision reflected the "different climatic issues" in Scotland as well as the geography which meant many more people received their fuel supplies "off-grid".
The move was angrily condemned by Liberal Democrat leader Tim Farron who said the Conservatives were behaving as "utter hypocrites".
"How can they take cash off English pensioners and then give it to Scottish pensioners? It looks like a cheap election bung and it won't wash," he said.
Mrs May, campaigning in Scotland, said the Conservatives would continue to ensure the least well-off pensioners were protected while ensuring fairness across the generations.
"We have devolution in the United Kingdom and as a government we have given the Scottish government significant powers in relation to welfare and they make a number of decisions about various welfare benefits in Scotland," she said.
"The decision we have made about winter fuel payments is that we will continue to ensure that the least well-off pensioners are supported but there is a principle of fairness."
Earlier, Labour claimed five-out-of-six pensioners – around 10 million people – would lose their entitlement to the winter fuel allowance as a result of the Conservative changes.
Visiting a community centre in Bedford, Mr Corbyn said: "We already have hypothermia deaths in winter, we already have fuel poverty in this country, that will get worse."
Meanwhile the Institute for Fiscal Studies said that up to one-in-six people in their 70s - between 12% and 17% - would lose eligibility for state support for the cost of their care while living at home.
Under the plans set out in the Conservative manifesto on Thursday, the party said it would not go ahead with the proposed £72,000 limit on care costs after which people would be entitled to state support.
Instead, people with assets of less than £100,000 – including the value of their home – will be protected from the costs of social care, although for the first time those receiving care in their home will have to pay as well as those in residential care.
However, Dr Wollaston said that by removing the cap, it would leave people unable to get insurance to cover their future care costs as it would be impossible to know what the final bill might be.
Writing in The Times, she said: "The dropping of the care cap sadly leaves social care uninsurable leaving in place the miserable lottery of care costs."