BORIS Johnson is expected to face questions this week over the veracity of his election promises after his manifesto was called into question by Labour and fact-checkers.

The Prime Minister's pledge of boosting the NHS with another 50,000 nurses secured headlines following the Conservative Party manifesto launch, while his promise of an extra £1 billion a year for social care is said to fall short of what is required.

Labour said the nursing figure was disingenuous when it included 19,000 nurses who the Tories wanted to re-train, and another 12,000 from overseas.

It means only 19,000 posts would be filled by new nurse trainees enjoying the return of maintenance grants - bursaries scrapped by former Tory chancellor George Osborne.

A Tory source confirmed this following the PM's speech, telling reporters: "We know that we have an issue with retention of the nursing workforce and so we would have plans to keep more nurses in the profession."

Sally Warren, director of policy at the King's Fund, said the Conservatives' funding pledge for social care - which was already announced before the manifesto unveiling - is "a couple of billion pounds short a year" of what the sector needs.

Warren, who is a former director of social care policy at the Department of Health, told BBC Radio 4's Today programme: "The money we've seen from the Conservatives yesterday is not going to be enough to continue to meet demographic pressures as our population ages over the next five years.

"So the money isn't enough and all the money would be doing would be to continue funding the current system, and that current system is widely seen to be very unfair for people who need to use it, and it has been struggling to be able to have enough funding to deliver high quality care.

"We do need a fundamental reform of the system. The Conservatives have been promising a green paper for more than two-and-a-half years, that green paper could have started a process of seeking consensus and they haven't yet published such green paper."

Pressed on what happened to the plan the Prime Minister said was "already prepared" to fix the social care crisis, Culture Secretary Nicky Morgan told the Today Programme: "Well I think there has been work going on but it's not in a stage yet in order to be launched, and I think that actually what you see overall in the manifesto, and I think quite right, because the second part of our campaign is about unleashing Britain's potential."

Shadow health secretary Jonathan Ashworth said: "The Conservatives' claim on nurses is frankly deceitful - the sums simply don't add up.

"First we had Johnson's fake 40 new hospitals, now we have his fake 50,000 extra nurses."

Ashworth also retweeted a Shropshire Star article about the full-time A&E at Princess Royal Hospital in Telford being replaced by an A&E Local which will only be open during "core hours".

The shadow health secretary wrote: "So first Boris Johnson mislead the people of Canterbury saying they would get a new hospital and it turns out they won't. Today he told people in Telford he would save their A&E and it turns out he won't.

"You simply can't believe a word he says when it comes to our NHS."

Meanwhile, independent fact-checking organisation Full Fact pulled the Tory leader up on his claim that his ministers would increase day-to-day government spending by only £3 billion.

The figure is small compared to Labour's promised £83 billion increase in spending, paid for by higher taxes on big businesses and the highest 5% of earners.

But Full Fact said, despite Chancellor Sajid Javid promising the "most transparent costings that have ever been published in British electoral history", the Tories had not explained how every pledge in the manifesto would be funded.

Chief executive Will Moy said the Conservative Party could "do more to meet the standards we expect" when it came to providing voters with "accurate and honest" information in the run up to polling day on December 12.

As the campaign enters its final two-and-a-half weeks, party leaders are set to see their promises put under the microscope, with forensic interviews by the BBC's Andrew Neil scheduled.

SNP leader Nicola Sturgeon will be the first to be quizzed on Monday evening, before the spotlight is put on Labour's Jeremy Corbyn on Tuesday.