David Cameron has renewed his call for the watchdog that sets MPs' pay to rethink a 10% salary hike.

The Independent Parliamentary Standards Authority (IPSA) says there appears to be no "material" reason to stop the increase from the current £67,060 to £74,000.

But Number 10 is sending a letter to the watchdog repeating the Prime Minister's opposition to the pay hike for members.

"We're writing a letter to IPSA to reiterate we stand by the detailed submission we had already made to them last year saying we think this rise is wrong," a Downing Street source said.

The Prime Minister is under growing pressure over the planned rise at a time when the rest of the public sector is restricted to 1% increases.

Frontrunners in the Labour leadership race - Andy Burnham, Yvette Cooper and Liz Kendall - have also made it clear they will not keep the cash.

A number of Tories are also thought to be planning to donate the benefits, including Education Secretary Nicky Morgan, who said she would increase the amount of money she gives to charity.

Mr Cameron previously described the pay rise as "simply unacceptable".

Sky News Political Correspondent Sophy Ridge said: "The Government is doing this because they know exactly how this would play with many people outside of Westminster - the idea that MPs are getting a £7,000-a-year pay hike at a time when other people find their pay is not going up as quickly as they'd like.

"The difficulty of course is that IPSA was set up in the wake of the expenses scandal as an independent body, really free from government meddling.

"Until now, the line from Number 10 is that they don't want to get involved in that process, but at the same time they do want to make their opposition to the pay rise heard."

Unless a consultation produces "new and compelling evidence" by the end of June, the pay rise will go ahead, backdated to 8 May.