Sir Keir Starmer faced the largest Commons revolt of his leadership As he pushed through "cruel" changes to the winter fuel payment yesterday.
Despite warnings from some that the raid might prevent elderly people from turning on their heaters this winter, dozens of Labour MPs disobeyed a three-line whip.
Only one Labour MP voted against the proposal, as many opponents were intimidated by the whips' threats of party suspension.
However, about 50 people showed their displeasure by not partaking.
With the help of his sizable Commons majority, the prime minister pushed through the controversial reduction by 348 votes to 228.
Today in the Lords, opponents will attempt one more effort to thwart the idea.
However, 10 million pensioners received a warning yesterday night that it was highly likely they may not get payments of up to £300 this winter.
Labour had 'declared war' on seniors, according to former work and pensions secretary Esther McVey, who also accused ministers of a 'cynical political calculation' that allowed the Government to afford to punish retirees since they were less likely to vote Labour.
“This Government have been telling pensioners they didn't want to do this, but tough financial decisions must be made – but we all know that's poppycock, that wasn't the Government's message to the already highly paid train drivers, when they met them, money was no object, have as much as you want,” she said.
The secretary added, “The public are not as stupid as this Government thinks they are.”
Veteran Tory MP Sir Edward Leigh also called the raid on pensioners a 'punishment beating'.
