What the manufactured row between the Tories and Labour over Trident renewal shows that they are as they are in many policies in accord.
This could mea nthat after May rather than the SNP putting Ed Miliband into NO 10 . Labour will at least for a period ensure David Cameron continues as Prime Minister.
Let us suppose the result of GE2015 leaves the Tories with the Lt not enough for a majority . The LibDems have enough seats to give them a Coalition Majority but they are temporally without a leader (Nick Clegg having lost his seat ) and there is no desire to take part in another toxic coalition
Nevertheless Cameron possibly with the support of the DUP presses on as Prime Minister.
On the first Queen Speech Trident and a in out EU referendum plays a prominent role but the rest of the speech is somewhat moderate
Plaid and the SNP ,Greens and Plaid together with the LibDems vote against it.
Labour however abstain citing that there is no desire for another election.
Basically Labour bide their time until after the EU election whatever the result they bring forward a Vote of no Confidence.
After all despite Michael Fallon announcing that the conservatives' manifesto will have a commitment to build four new nuclear missile-armed submarines, and accosting Labour of using the nuclear deterrent as a "bargaining chip" with the SNP, Ed Miliband has said Labour was committed to renewing the Trident system.