The current terms of Britain's membership of the European Union are "disastrous", cabinet minister Chris Grayling has said.

The intervention comes after former leader William Hague, another EU critic, told ITV News leaving the EU would have devastating consequences.

Mr Grayling, one of the party's most prominent Eurosceptics, wrote in the Telegraph that the path to ever-closer union in Europe was one "that the UK will not and should not follow".

David Cameron recently announced that ministers would be allowed to campaign on either side ahead of the EU referendum, but only once he has completed renegotiation on Britain's relationship.

ITV News Political Editor Robert Peston said the article indicated it was "inevitable" that the Commons Leader would campaign to leave once the talks were finished.

In the article, the former Justice Secretary said it was right Mr Cameron attempted to "seek new terms for our membership", and stopped short of saying Britain should leave if the talks fail to produce a satisfactory outcome.

However, he wrote: "I am someone who believes that simply staying in the EU with our current terms of membership unchanged would be disastrous for Britain.

"That's why I have always believed that it is imperative that his renegotiation takes place and delivers as much potential change as possible. It is in the interests of all Eurosceptics and of our country."

A senior source said Downing Street was "completely relaxed" about Mr Grayling's comments, after the rules governing ministers' behaviour were laid out in a minute by the Prime Minister last week.