Labour has a 16-point lead over the Tories, with the Lib Dems in fifth place behind Ukip and the Greens.
Cable has previously suggested that the coalition could end early, a demand now made by the Lib Dem peer.
With the general election result so uncertain, leadership contenders in the Tories, Labour and the Lib Dems are making themselves known.
Party writes to Jeremy Heywood asking whether Coetzee's involvement in Lib Dem election strategy has breached the special advisers' code of conduct.
The rise of UKIP and the fall of the Lib Dems explains why Labour is maintaining a lead approaching the final year of this parliament.
Rather than Jeremy Browne, the party needs a centre-left figurehead, such as Tim Farron, to revive its fortunes.
How many know that the party still aspires to abolish tuition fees and plans to review the bedroom tax?
The ambitious Lib Dem is positioning himself as the "continuity candidate" in a future leadership contest.
Policies such as cutting the top rate of tax, reducing NHS spending and introducing for-profit free schools are politically toxic.
With each week, the party is giving more power and responsibility to individuals to shape their own destiny - the essence of liberalism.