* British Deputy Prime Minister Clegg criticises spending cuts
* Coalition government put austerity drive at heart of agenda
* Data expected to show UK economy shrank at end of 2012
LONDON, Jan 24 (Reuters) - British Prime Minister David Cameron risked harming the economic recovery early in his premiership because his flagship austerity policy cut spending too deeply, his deputy said on Thursday, in comments that could deepen rifts in the coalition government.
Nick Clegg, leader of the Liberal Democrats, the junior coalition partner, said it had been a mistake to make such big cuts to capital spending, an area that includes new roads, schools and hospitals.
His comments came a day before official figures are expected to show the British economy shrank in the fourth quarter of 2012 and risks falling into its third recession since the financial crisis if the weakness persists early this year.
A bleak set of GDP figures on Friday would cast more doubt on Britain's triple-A credit rating and pile pressure on Cameron and finance minister George Osborne to soften their austerity measures and do more to stimulate the economy.
"If I'm going to be sort of self-critical, there was this reduction in capital spending when we came into the coalition government," Clegg said in an interview with The House, a weekly political magazine.
"We have all realised that you actually need, in order to foster a recovery, to try and mobilise as much public and private capital into infrastructure as possible."
Cameron and Clegg made reducing Britain's budget deficit - which hit a record 11.2 percent of GDP before the 2010 election - their biggest priority when they came to power.
The main opposition Labour Party repeatedly attacked their public spending cuts, saying attempts to balance the books were too strong and too deep and had choked the economic recovery.
In December, the government set out new measures aimed at boosting growth, including looser planning rules and investment in railways, roads and schools.
Clegg and Cameron promised this month to stick with their coalition until an election due in 2015, despite falling out on a range of issues, most recently on Britain's ties with Europe.
Osborne said on Thursday he would stick with his fiscal plans.
The Liberal Democrats have seen their poll ratings tumble since they took power with the larger Conservatives. Clegg upset many supporters by breaking a promise not to raise university tuition fees and has been accused of turning his back on his party's values to maintain the coalition.
Labour, leading in polls, seized on Clegg's comments as an admission the coalition had mishandled the recovery.
"This is the first admission that this government has made serious mistakes on the economy," Labour finance spokeswoman Rachel Reeves said.