The UK Prime Minister was addressing attendees at a Conservative Friends of Israel annual lunch.
The Labour leader made the pledge during a major speech on immigration in Great Yarmouth.
Miliband is expected to deliver the speech in Great Yarmouth ahead of the 2015 General Election.
The Labour MP is making the move to to stop voters picking pro-independence parties next may.
Aberdeen North MP Frank Doran made the initial comments during a House of Commons debate.
Miliband woos voters who think austerity is right, but the coalition's deficit reduction plan is unfair.
Thought of an alliance between Salmond and Miliband is enough to send shivers down right-wing spines.
Shadow Health Secretary expected to announce cancer policy pledge
The British Election Study says the damage to Labour's core support has already been done.
Labour leader promises to allow 16 and 17 year olds chance to vote by May 2016 if elected.
UK education should not be under control of politicians who only chase political or popular agenda.
Cameron pledge to reduce net migration to the UK to less than 100,000 by May 2015.
Promises haven't been kept - make no mistake about it.
The findings are part of a four-year project from Aston University academic Professor John Gaffney.
The heavyweight says he would be 'more interested' after a Labour majority.
The Labour leader is expected to attack the government over the 'cost of living crisis'.
The poll from Lord Ashcroft put Clegg on 31% and Oliver Coppard, the Labour candidate, on 28%.
Is Ed Miliband's mansion tax proposal is so horrid that it will make all those lovely luvvies abandon their luxury homes in London and go and live abroad?
The former England footballer says Miliband keeps 'banging on about' fairness.
Jolie says, 'I'm quite responsible about money' but Miliband's mansion tax 'could put me off'.
But former UK Prime Minister Gordon Brown warned that the move could be a 'Trojan Horse'.
IBTimes UK wants your opinions on Labour's stance ahead of the 2015 General Election.