Mr Burnham was expected to tell a party meeting in Liverpool on Tuesday that Liberal Democrat MPs hold ‘the key to the future of our NHS’.
The coalition government relies on its 57 Lib Dem MPs for a working majority in parliament.
Mr Burnham will call for deputy prime minister Nick Clegg – due to address the Lib-Dem conference in the city next month – to 'explain why the reforms are being forced on the NHS’.
The former health secretary has launched a 'Save Our NHS Campaign' in opposition to the plans, which he says are 'unnecessary and dangerous' and will cause waiting times to rise.
In a letter to Lib Dem MPs ahead of his speech, he wrote: ‘I do not believe the people who voted for you at the election voted for such a radical break-up plan.'