* Miliband says would not support "irresponsible strikes"
* Criticises 2003 U.S.-led invasion of Iraq
* Rejects leftist label
(Adds new quotes on Iraq)
By Adrian Croft
MANCHESTER, England, Sept 28 (Reuters) - Britain's new opposition leader said on Tuesday economic policy should focus on growth, not just cutting the deficit, and he would not support "irresponsible strikes" against planned spending cuts.
Ed Miliband, 40, set out in his first major speech as Labour Party leader to address concerns he would be lax on cutting the deficit or a would-be left-winger in the thrall of the unions.
Labour was ejected from power after 13 years in a May election, replaced by a Conservative-Liberal Democrat coalition that plans deep spending cuts to reduce a record peacetime budget deficit left behind by Labour.
"I won't oppose every cut the coalition proposes," Miliband told his party's annual conference in the northwestern city of Manchester.
"And come the next election there will be some things they have done that I will not be able to reverse," he said.
Miliband beat his older brother David to become Labour leader on Saturday thanks to strong union support, prompting accusations he would be beholden to the unions. He sought to show that would not be the case.
"I have no truck, and you should have no truck, with overblown rhetoric about waves of irresponsible strikes. The public won't support them. I won't support them. And you shouldn't support them either," he said.
With public concern about the cuts growing, Labour edged ahead of the centre-right Conservatives for the first time in three 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 Labour government, particularly then Prime Minister Tony Blair's decision to back the 2003 U.S.-led invasion of Iraq.
"I do believe that we were wrong, wrong to take Britain to war and we need to be honest about that," he said.
He criticised Labour's handling of the economy, saying Britain was too exposed to financial services and the party should 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 bad situation worse by embarking on deficit reduction at a pace and in a way that endangers our recovery," he said.
"The starting point for a responsible plan is to halve the deficit over four years, but growth is our priority and we must remain vigilant against a downturn," he said.
Without a plan for growth, there would be no credible plan for deficit reduction, he said.
He called for a higher bank levy that would allow the government to do more to protect public services and benefits.
The coalition plans to virtually eliminate the deficit by 2015, when the next election is due.
Miliband called for higher pay for low-paid workers and took aim at high executive pay. Employers should not be allowed to exploit migrant labour in order to undercut wages, he said.
A relaxed Miliband gave a personal speech, recounting how his Jewish father took refuge in Britain after fleeing the Nazis in 1940 and how his Polish-born mother spent the war on the run sheltering in a convent.
Miliband rejected the "Red Ed" label adopted by some newspapers and said he would fight for the centre ground.
The Institute of Directors, a business group, said measures Miliband was proposing would hurt business and said it detected a drift away from Labour's previous efforts "to talk up a pro-enterprise agenda".