JEREMY Corbyn has challenged Theresa May to spell out the impact of the Conservatives’ so-called "dementia tax" social care policy as Labour seeks to pile pressure on what it believes has become one of the Tories’ biggest weaknesses of the campaign,

The Labour leader said it was "staggering" that pensioners south of the border were not being told at what level the Prime Minister intended to cap social care costs or how many elderly people would face losing the winter fuel payment worth up to £300; the Scottish Conservatives have said they would not means-test the benefit in Scotland.

The Opposition calculated the Tory plan to means-test winter fuel payments could hit up to 10.8 million pensioners in England and Wales while people who required social care could face spending up to 42 per cent of the value of their estates if the cap were set at £100,000.

Mr Corbyn said: "It is staggering that just six days from polling day millions of pensioners still don't know what's in store for them if they are unlucky enough to get dementia or any other condition that needs care in the home.

"The dementia tax is itself unfair but what's made matters even worse is the way Theresa May announced a cap and then failed to say how much it would be.

"Alongside this, older people face the additional uncertainty of not knowing who will be eligible for a winter fuel payment. The introduction of a means test could mean more than 10 million people losing the payment.

"Theresa May's only offer to pensioners is insecurity and cuts. Labour will stand up for older people by maintaining the triple-lock on state pensions, investing £8 billion into social care over the next parliament and protecting winter fuel payments and free bus passes," he added.

The Prime Minister suffered a "wobble" after the Tory manifesto launch when she U-turned and said there would after all be an "absolute cap" on social care costs after Tory candidates reported a revolt on the doorsteps.

Labour’s new attack came as a new poll suggested it was continuing to make ground on the Conservatives as the two main parties prepare for the final push towards polling day.

Ipsos Mori's Political Monitor showed the gap between the two main parties closing to five points with the Tories on 45 per cent - down four on two weeks ago - while Labour are up six on 40; their highest showing in the campaign to date.

While Mrs May remains voters' preferred choice for prime minister, her personal rating has slipped six points on 50 per cent. Meantime, one in three people – 35 per cent - now support Mr Corbyn, an increase of six points for the Labour leader.

John McDonnell, the Shadow Chancellor, expressed the growing confidence in the Labour team, declaring: "10 on 10, we’re going to win."

On the campaign trail in York, the Labour leader used a speech to outline his party’s industrial strategy, insisting that the "vast majority" of the one million good quality jobs Labour has pledged to create would go to British workers; a move reminiscent of Gordon Brown’s famous pitch of “British jobs for British workers”.

Mr Corbyn said Labour would build an economy where "everyone shares in our country's wealth".

Asked if he could guarantee that all or a proportion of the one million jobs would go to British workers, he said after the speech: "They would obviously be for people looking for work, the vast majority will be for people coming out of our schools and our colleges and our universities, and we will not allow anyone to only recruit overseas for jobs here.

"They've got to recruit in an open way so that everyone gets a fair chance. So we will not be allowing companies to import an entire workforce from overseas.”

But, speaking at the York Science Park innovation centre, the party leader made clear that Britain had to have a relationship with the rest of the world and maintain the close connection between the universities and industries.

"We're in the laboratory now, what's being discovered here, what's being researched here, similar kind of things are being done in all parts of the world. Science grows when scientists work together, not in isolation."