Labour stretches into biggest lead over the Tories

Labour has established its biggest opinion poll lead since the general election as Britain's economic woes deepen and coalition tensions intensify, according to the latest poll of polls for i.

With political leaders preparing for their long summer break, the latest snapshot of their parties' electoral health underlines the backlash faced by the Coalition partners this year.

Labour's support rose to an average of 42 per cent last month, nine points ahead of the Conservatives on 33 per cent. The Liberal Democrats slipped back to 11 per cent.

Mr Miliband's margin of victory would be even bigger if – as looks increasingly possible – the next election uses the current boundaries.

David Cameron is keen to settle a key Coalition flashpoint before he leaves for his post-Olympics holiday by announcing that plans for a part-elected House of Lords are being scrapped. The Liberal Democrats are threatening in response to veto plans to cut the number of parliamentary constituencies. Talks are continuing over the issue, with the aim of announcing a compromise ahead of moves to give fresh impetus to the Coalition in the autumn.

Sources in both parties dismissed suggestions yesterday that Downing Street had begun informal discussions with senior Conservatives over splitting the Coalition early.

According to one report, the Liberal Democrats would pull out a year before the election, due in May 2015, and support the Tories only in a no-confidence vote or over budget measures. But a senior Liberal Democrat source said: "The Coalition is here to stay until 2015."

However, Brian Paddick, twice the party's candidate for London Mayor, told Sky News: "In the run-up to the next election, the two parties have got to separate themselves to present two different manifestos, two different options to the public."

A nine-point advantage would be enough to secure an overall majority of 86 for Labour in an election fought on the proposed new constituency boundaries, while the Lib Dems would face electoral meltdown.