As Lib Dem supporters revolt over their party’s direction, Labour supporters tell Ed to do a deal with Clegg

Making the Liberal Democrats a party of government and of the centre are the two elements to the Nick Clegg project. His external critics struggle most with the latter, seeing him as a Conservative, and his internal ones the former, uncomfortable with power's compromises.

These complaints shouldn't distract from how close he is to completing his project. In anticipation of another hung parliament, Conservatives and Labourites are keen to be on good terms with him. How would we regard Clegg if he were to serve in government until 2020? And with which party would he prefer the second half of this period to be served?

After a decade in government, there would be voters unable to remember the Liberal Democrats in opposition. Serving half of this time with the Conservatives and half with Labour would reinforce their centrist claims. Which is why Clegg may favour changing governing partners in two years.

Labour has synchronised policies with his party on a mansion tax, votes at 16 and a 2030 decarbonisation target, which makes it easier than otherwise for him to make this transition. According to polling that YouGov have done for Labour Uncut, 50 per cent of Labour supporters think Labour should go into coalition with the Liberal Democrats – even if it means Nick Clegg staying in government as Liberal Democrat leader – if that's necessary to stop a continuation of the current coalition.

However, while government with the Liberal Democrats was thought to help detoxify the Tory brand, we find no evidence that government with the Liberal Democrats would strengthen the Labour brand. Eight per cent more voters would trust a majority Labour government to take the right decisions on the economy than a Labour-Lib Dem one.

Minority government shouldn't be ruled out. Majorities, though, require what Clegg is failing to deliver: command of the centre. Clegg's pitch for the centre depends upon having the fiscal discipline and independence from the trade unions that Labour lacks, as well as the fairness that the Conservatives miss. But the pitch is falling flat.

YouGov report almost 2 in 3 2010 Liberal Democrat voters think the party has changed for the worse since the last election. Even among current Liberal Democrat supporters, more think they've changed for worse (36%) than for the better (20%) since the election. 

Even though Len McCluskey threatens to pull Labour to the left and the Nigel Farage the Tories to the right, Clegg's hold on the centre remains weak. Some would attribute this to his personal failings and others to the structural limitations of multi-party government. The public would much prefer single party government. 57 per cent favour either a Labour or Tory majority government, compared with 22 per cent favouring either a Tory-Lib Dem or Labour-Lib Dem coalition, according to YouGov.

For the Conservatives to form a majority, they must show that they have the heart that Clegg says they don't. For Labour to do so, Clegg's claims about profligacy and trade union capture must be exploded. These are the fundamental barriers to the two largest parties retaking the centrist terrain that Clegg has sought but failed to dominate.

Conservatives shouldn't show compassion or Labour prudence because it would make future government with the Liberal Democrats easier. But because - no matter what pressures Cameron and Miliband will come under to pacify their supporters in coming weeks - majority governments will continue to be forged on the centre.

Labour Uncut will be suggesting how Labour might do this in a new pamphlet for Labour party conference, titled Labour's manifesto uncut: How to win in 2015 and why. The bold pitch for the centre that this pamphlet recommends is the most likely way to return Labour to government and would be the party's gravest threat to Clegg's project.

Jonathan Todd is the economic columnist for Labour Uncut. ‘Labour’s manifesto uncut: How to win in 2015 and why’ is launched on September 23 at the PragRad fringe at the Labour  Party conference.