VAT looks set to remain at 20 per cent or less until 2022 after both the Conservatives and Labour promised not to increase the tax on goods and services if they won the General Election.

However, Theresa May signalled she would scrap the Tories' flagship triple "tax lock" pledge, which also rules out increases to income tax and National Insurance.

In March, Chancellor Philip Hammond had to perform an embarrassing U-turn on raising National Insurance contributions for Britain's growing army of the self-employed because the 2015 Tory manifesto ruled out any tax hikes at all. Now, the Prime Minister looks set to give a future Conservative government more flexibility in the party's forthcoming election prospectus.

She said it was her intention to cut taxes on "working families" while John McDonnell, the Shadow Chancellor, also promised to "protect middle and low earners"; yet neither defined exactly who they meant. Mr McDonnell recently said that those earning more than £70,000 a year were "rich".

Mrs May told ITV's Peston on Sunday: "We have no plans to raise the level of tax. In relation to specific taxes, we won't be increasing VAT."

But asked if she would maintain the Tories' 2015 triple tax lock, which pledges no increases to income tax and national insurance as well as VAT, she told BBC One's Andrew Marr Show: "We have absolutely no plans to increase the level of tax but I'm also very clear that we don't want to make specific proposals on taxes unless I'm absolutely sure that I can deliver on those."

Mr McDonnell said Labour was committed to a "fair taxation system" and suggested "giveaways" to corporations and the rich would be reversed if Jeremy Corbyn became PM, to pay for pledges to spend on the NHS and schools.

He told Robert Peston: "Look, there's going to be a barrage of attacks (over spending and tax increases), but the issue around fair taxation is that we will protect middle and low earners.

"I will say also, we will not increase VAT and I want you to ask Theresa May that question as well because if you remember last time the Tories promised no increase in VAT and then they increased it afterwards and then that falls on, that's a regressive tax, that falls on some of the poorest and middle earners as well, so that's one guarantee we're giving."


The Shadow Chancellor also criticised Mrs May after she suggested she could reform the pensions triple lock.

Labour has committed to maintaining the triple lock, which ensures the state pension increases in line with wages, inflation or by 2.5 per cent; whichever is highest. But Mrs May suggested she could modify the flagship Tory policy.

She told Andrew Marr: "Under a Conservative government the state pension will still go up every year of the next parliament. Exactly how we calculate that increase will be for the manifesto and, as I have just said, you will have to wait for the manifesto to see what's in it."

Mr McDonnell said breaking the triple lock would plunge pensioners into poverty. "What we saw from the research this morning, that was published this morning, you'll see that if they break the triple lock it'll be some of the poorest that lose out; also, it'll be young people for the future. 

"And the research that was published this morning by Hymans will tell you, pensions will not be protected. I do not want to go backwards, I do not want pensioners going back into poverty again."

Mrs May also hinted she would go further to tackle the social care crisis in England, building on the £2 billion announced for the sector by Mr Hammond in the Budget.

She told the BBC: "There are three stages to this, there's the short-term, £2 billion extra going in, there's the medium term, which is about spreading best practice around the country, and longer term we need to have a sustainable solution for social care.

"And yes, we have been working on that sustainable solution and these issues, an issue like this, about the impact of our ageing population, is exactly the sort of long-term issue that I want to address for the future."

The PM, accused of running scared by her opponents by not agreeing to participate in head-to-head TV debates, made clear she would not be changing her mind, stressing: "There isn't going to be any change."