Mark Pack, co-editor of the Liberal Democrat Voice website, said: "Party members will understand the underlying point Nick Clegg was making - that this isn't a single-issue coalition."

First, Mr Cameron would struggle to justify removing Dr Fox after persisting with Vince Cable, the Liberal Democrat business secretary, who barely bothers to hide his distaste for the Conservatives.

He said that his party was willing to give ground on a key Liberal Democrat demand and move towards a more representative voting system.