Vince Cable says the Lib Dem leader took a "gamble" by campaigning on Europe, while Lynne Featherstone says her party has lost its "humanity".
Cameron fears the collapse of the coalition. Labour fears a more popular centre-left leader.
The party's pledge to build 300,000 homes a year is barely known.
Party president also says Lib Dems will not withdraw from the coalition.
It would enhance his bargaining power, while the Tories can remind him that they allowed a vote on AV.
The combined attacks by the Lib Dems and Labour are further weakening public support for Gove's project.
The party's visceral attacks on the Lib Dems show it is staking everything on a majority.
The inclusion of the party would help to split the left-wing vote and harm Labour and the Lib Dems.
The party is determined to deny Clegg the chance to make a fresh appeal.
Rather than preparing for another hung parliament, Labour is focused on "crushing" Clegg's party.