By Adrian Croft

MANCHESTER, England, Sept 28 (Reuters) - Britain's newopposition leader said on Tuesday economic policy should focuson growth, not just cutting the deficit, and he would notsupport "irresponsible strikes" against planned spending cuts.

Ed Miliband, 40, set out in his first major speech as LabourParty leader to address concerns he would be lax on cutting thedeficit or a would-be left-winger in the thrall of the unions.

Labour was ejected from power after 13 years in a Mayelection, replaced by a Conservative-Liberal Democrat coalitionthat plans deep spending cuts to reduce a record peacetimebudget deficit left behind by Labour.

"I won't oppose every cut the coalition proposes," Milibandtold his party's annual conference in the northwestern city ofManchester.

"And come the next election there will be some things theyhave done that I will not be able to reverse," he said.

Miliband beat his older brother David to become Labourleader on Saturday thanks to strong union support, promptingaccusations he would be beholden to the unions. He sought toshow that would not be the case.

"I have no truck, and you should have no truck, withoverblown rhetoric about waves of irresponsible strikes. Thepublic won't support them. I won't support them. And youshouldn't support them either," he said.

With public concern about the cuts growing, Labour edgedahead of the centre-right Conservatives for the first time inthree years in a YouGov poll in the Sun newspaper on Tuesday.

"GROWTH IS OUR PRIORITY"

Proclaiming that a new generation had taken over Labour,Miliband distanced himself from some key policies of the Labourgovernment, particularly then Prime Minister Tony Blair'sdecision to back the 2003 U.S.-led invasion of Iraq.

"I do believe that we were wrong, wrong to take Britain towar and we need to be honest about that," he said.

He criticised Labour's handling of the economy, sayingBritain was too exposed to financial services and the partyshould have resisted financial market deregulation.

Miliband said he was serious about reducing the deficit.

"But what we should not do as a country is make a badsituation worse by embarking on deficit reduction at a pace andin a way that endangers our recovery," he said.

"The starting point for a responsible plan is to halve thedeficit over four years, but growth is our priority and we mustremain vigilant against a downturn," he said.

Without a plan for growth, there would be no credible planfor deficit reduction, he said.

He called for a higher bank levy that would allow thegovernment to do more to protect public services and benefits.

The coalition plans to virtually eliminate the deficit by2015, when the next election is due.

Miliband called for higher pay for low-paid workers and tookaim at high executive pay. Employers should not be allowed toexploit migrant labour in order to undercut wages, he said.

A relaxed Miliband gave a personal speech, recounting howhis Jewish father took refuge in Britain after fleeing the Nazisin 1940 and how his Polish-born mother spent the war on the runsheltering in a convent.

Miliband rejected the "Red Ed" label adopted by somenewspapers and said he would fight for the centre ground.

The Institute of Directors, a business group, said measuresMiliband was proposing would hurt business and said it detecteda drift away from Labour's previous efforts "to talk up apro-enterprise agenda".