Theresa May has ruled out increasing VAT for the next five years but has refused to reveal whether she will increase other taxes for higher earners.

The Conservatives are understood to be considering an election pledge not to increase the total tax take - as a proportion of the economy - but are poised to abandon David Cameron's commitment not to increase income tax and national insurance.

Philip Hammond was recently forced to abandon plans to increase National Insurance for the self-employed as it risked breaking the 2015 Tory election manifesto, but a rewritten tax pledge would allow such a rise.

The Prime Minister has repeatedly refused to speak about her tax plans in detail since launching the election campaign last month but yesterday ruled out any rise in VAT. She refused to give a similar pledge on income taxes.