A poll has revealed that two-thirds of Conservative MPs support tax relief on private health insurance, reigniting controversy over the party’s commitment to the NHS.

Chancellor Alistair Darling accused the party of having “two faces” when it came to healthcare.

Shadow health secretary Andrew Lansley insisted the Conservatives were committed to ensuring people had access to high quality healthcare without the need to take out private insurance.

However, he said a “serious debate” was needed on how healthcare was best delivered through the NHS.

Some 66 per cent of Tories supported tax relief on standard rate income tax for private medical insurance, according to a poll of 150 MPs.

In contrast, the ComRes poll for private hospital group BMI Healthcare revealed that 1 per cent of Labour MPs and 5 per cent of the Liberal Democrats backed the idea.

More than half the Conservatives - 55 per cent - backed the introduction of tax relief on private healthcare fees, compared with only 1 per cent of Labour MPs.