Labour should run its own Yes campaign for the referendum on whether the UK should remain in the European Union, would-be party leader Andy Burnham said as he set out his stall on Europe.
The shadow health secretary - who is travelling to Brussels for talks with MEPs and the UK's ambassador to the EU - said Labour had to "learn the lessons" of the Scottish independence referendum campaign.
Critics say Ed Miliband's decision to join the Conservatives and other pro-union parties in the Better Together campaign promoting a No vote played a large part in the party's subsequent general election wipeout by the SNP north of the border.
Mr Burnham will promise to lead a "distinctive" campaign focused on issues such as preventing workers being "undercut" by EU immigrants, exclusive recruitment from overseas and strengthening enforcement of the national minimum wage.
"Even though Labour is in a leadership campaign, I am not going to let the EU debate be defined by David Cameron.
"Today, I will discuss with Labour colleagues in the European Parliament what a distinctive pro-European reform package will look like," he said.
"These are areas that David Cameron will not be focussing on and that is why we be raising them today to make the Labour case for Europe. Renegotiation cannot be a green light to turn the clock back and weaken employment rights.
"Labour will also learn the lessons of the Scottish independence referendum and it is my intention to have a separate 'Labour Yes' campaign."