Nick Clegg will attempt to restore his reputation among the Liberal Democrats today by launching a new attack on the "power and privilege" that has kept his party out of government for generations.
Days after the humiliation of seeing his efforts to produce a workable policy on the European Union founder, Mr Clegg will try to deflect attention on to a wider political settlement he claims is "hammered out in smoke-filled rooms" by his political opponents.
As he attempted to relaunch himself as a credible leader, it emerged that the Sheffield MP has also tried to bolster his green credentials, with colleagues revealing that he has started puttering around London on an eco-friendly moped to do his bit against global warming.
One of Mr Clegg's closest colleagues will make the revelation on television this morning, as his leader prepares for one of the most challenging performances of his life.
Asked if Mr Clegg will follow his predecessor's example of giving up a gas-guzzling vehicle to make an example of himself, the Lib Dem environment spokesman, Steve Webb, tells the GMTV Sunday programme: "Nick is experimenting with some sort of low-carbon moped for getting around London, so I'm sure there's a photograph coming of that. We can all have a little wind turbine on our roof that barely powers a light but actually what we need is systematic government policy."
In his first keynote speech as leader, to the party's spring forum in Liverpool, Mr Clegg will complain that his attempts to "design a new political system for the 21st century" have been hampered by the reluctance of Labour and the Tories to cooperate.
Mr Clegg claims he asked Gordon Brown and David Cameron to discuss his proposals to establish a "citizens' jury" of 100 people to join the political parties, churches and other groups in a constitutional convention designed to revolutionise the way Britain is governed. And he will propose a £25,000 cap on donations to political parties, a cap on spending and an end to big union donations and contributions from overseas as a first step towards cleaning up "old-style" politics.
"I wrote to David Cameron and Gordon Brown proposing such a convention just after Christmas," Mr Clegg will tell delegates at the end of the three-day gathering. "Dave suggested he and I gang up on Gordon. And Gordon sent me six pages of bureaucratic waffle. Only the Liberal Democrats will ever champion the sort of change we need. Only we can transform the system, because we aren't part of it."
Mr Clegg prepares to confront his party after facing his most uncomfortable week as leader since taking over from Sir Menzies Campbell in December.