Labour will attempt to ramp up pressure on the coalition by calling on Liberal Democrats to join them in condemning proposals to reintroduce O-levels and CSEs as "consigning young people to the scrapheap".
The party will use an opposition day debate in the Commons on Tuesday to claim Education Secretary Michael Gove's plans would be a "damaging leap backwards".
Gove's O-level plans are detrimental to young people, argue Labour
Details were leaked last week of proposals for pupils to take O-levels in traditional subjects such as English, maths, science and the humanities by 2016 while less able pupils would take old-style CSE qualifications.
But the move exposed deep divisions within the coalition. Lib Dem sources suggested they were "very, very hostile" to something that would create a two-tier system while Deputy Prime Minister Nick Clegg said he and Prime Minister David Cameron knew nothing about it.
Shadow education secretary Stephen Twigg will urge Lib Dems to back Labour in the non-binding vote.
Twigg said: "Michael Gove's plans to bring back the CSE are a cap on aspiration for young people.
"Re-introducing a two-tier system in secondary education, which was abolished by Margaret Thatcher in the 1980s, would be damaging leap backwards."
He added that Labour will "lead a debate in Parliament to shed light on the Education Secretary's plans and to make the case for reforming the secondary system for all children, not just the few.
"Nick Clegg has said that his party will not support a two-tier system that consigns young people to the scrapheap.
"Labour is calling on the Liberal Democrats to join us and vote against plans for a reintroduction of this regressive system in the House of Commons."
Labour decided to switch the subject of their debate from health to education following the backlash after the plans emerged.
It comes after the party secured an urgent question on the plans last week. Gove told MPs then that a two-tier system already exists and radical changes need to be made to make exams tougher and ensure the UK keeps up with other nations.
He added: "While there were undoubtedly improvements in our schools and by our teachers over the course of the last 20 years, those improvements were not sufficient to ensure that we kept pace with other jurisdictions."
