Ministers are set to ignore a manifesto commitment and scrap plans for a review of electoral systems, according to media reports.

A story in the Times on Friday suggested that senior Cabinet figures have united to block a promised study by the Department for Constitutional Affairs into alternative voting methods for Westminster elections.

Deputy prime minister John Prescott and health secretary John Reid are understood to have led the rebellion, with support from home secretary David Blunkett and foreign secretary Jack Straw.

The four heavyweights are all defenders of the first-past-the-post system and arch-enemies of the Liberal Democrats, who would benefit most from any move towards proportional representation.

Constitutional affairs secretary Lord Falconer was reported to have put to the Cabinet a proposal for the review, to be conducted in-house by his department, with the title, terms of reference, membership and timetable all thought to have been drawn up.

Labour promised the inquiry in its 2001 manifesto having reneged on a deal to offer a referendum on PR in its first term in power.

The review was set to take into account last year's Scottish and Welsh elections, which use an additional member system, and June's European polls, which were conducted under a closed list.

Several Labour MEPs are unhappy with the latter, which they feel has undermined their constituency links.

A government source told the Times: "It was all fine until ten days ago when suddenly there was a revolt by, basically, most of the heavyweight people in the Cabinet."

The move will anger Labour supporters of PR, who argue the party will have to find common ground with the Lib Dems eventually as its impregnable Commons majorities will not last indefinitely.

Lord Falconer is understood to have appealed to the prime minister to overrule his Cabinet colleagues.

But the Department for Constitutional Affairs refused to comment when approached by ePolitix.com.