The MPs' pay regulator has defied an outcry to confirm an 11 per cent hike, warning senior politicians that undermining its conclusions will lead to "disaster".

The Independent Parliamentary Standards Authority (Ipsa) said salaries would go up from the current level of £66,000 to £74,000 after the general election in 2015.

But it insisted pensions will be curbed and other benefits trimmed to ensure the overall changes are cost-neutral.

Ipsa chairman Sir Ian Kennedy said: "For the first time, MPs' pay and pensions will be set independently, and away from political deals cooked up in Westminster.

"We are sweeping away the out-of-date and overly generous benefits, and introducing a one-off uplift in pay. Crucially, thereafter MPs' pay will be linked to everyone else's."

The move sets the stage for a major political battle, with many backbenchers supportive of the salary increase but all three main party leaders condemning it.

Prime Minister David Cameron issued a veiled threat yesterday to abolish Ipsa if it presses ahead with the "simply unacceptable" planned rise.

His Liberal Democrat deputy Nick Clegg told LBC 97.3 radio this morning the hike was "incomprehensible and wholly inappropriate" at a time when rises in the rest of the public sector were limited to 1%. Labour leader Ed Miliband has also called for it to be dropped.

But Sir Ian insisted he would not be deterred by pressure.

"Parliament was clear in the wake of the expenses scandal that it was wrong for MPs to set their own expenses, salary, pensions and benefits," he wrote in The Times.

"That remains a position hard to argue with. We all know that MPs made a mess of these things for decades; the result was a disaster."

In a foreword to the report, the Ipsa board wrote: "We have a choice to make: either we say it is too difficult and ignore the issue for another number of years, or we address it with those sensitivities in mind.

"We choose the second option. We feel any other choice would be to abandon our responsibility, which Parliament gave us, to fix this problem once and for all.

"But we do understand the sensitivities. As we note above, we have committed that the reforms will not cost the taxpayer more.

"And, while we have concluded our review of the arguments and have resolved in favour of this package, we will conduct a review - as we are obliged by law to do - taking account of all the circumstances as they are in the summer of 2015."