LONDON: British Prime Minister Keir Starmer won a vote on his welfare plans on Tuesday at significant political cost as he suffered the biggest parliamentary rebellion of his premiership and was forced to back down on key parts of the package.

After his lawmakers pushed him into a series of embarrassing U-turns to sharply scale back plans to cut benefits, lawmakers in the House of Commons gave their initialapprovalto apackage of measures Starmer says are vital to securing the future of the welfare system.

But the scale of the rebellion with 49 Labour lawmakers voting against the reforms underlined the prime minister`s waning authority.

A year after winning one of the largest parliamentary majorities in British history, Starmer has seen his personal approval ratings collapseand been forced into several policy reversals by his increasingly rebellious lawmakers.

`It`s been a bumpy time tonight,` work and pensions minister Liz Kendall told reporters after a session of parliament when lawmakers took turns to mostly criticise the planned changes.

`There are definitely lessons to learn from this process.

Starmer came into office last year promising his big parliamentary majority would bring an end to the political chaos that defined much of the Conservative Party`s 14 years in power. But the revolt over the welfare bill underlines the difficulty he has pushing through unpopular changes.

In the run-up to the vote, party enforcers, known as `whips`, had been locked in frantic last-ditch lobbying of undecided members of parliament to try to win their backing. -Reuters