YouGov has Lib Dems on 14%
The overnight YouGov figures for the Sun had voting intentions of CON 43%, LAB 35%, LDEM 14%(!). The changes are well within the margin of error of the recent levels of support that the parties have been showing and it is the sort of figure we'd expect to pop up occassionally with the Lib Dems floating around 15% in recent polls, but it's worth recording that this is the Liberal Democrats lowest level of support since well before the general election. On a uniform swing it would reduce them to a rather sorry 16 seats, though in practice incumbency does tend to give Lib Dem MPs some degree of protection.
UPDATE: I said in the previous post that we hadn't had a Populus voting intention poll since the General election. Since then they've put up the tables from their post-budget poll, which did have voting intentions after all, though I don't think the Times reported them at the time. They are, of course, long out of date now, having been conducted in late June, but for the record they showed CON 39%, LAB 33%, LDEM 18%.