MPs have said the government is “still in peril” over its plans for social care funding, with several expecting a government climbdown as peers warned they would force the issue back to the Commons. The government suffered a significant rebellion on Monday night but carried the change to the social care cap with a slimmed-down majority. The number of abstentions from discontented MPs is likely to worry whips if peers in the House of Lords return an amended bill to the Commons. On Tuesday the chair of the Treasury select committee, Mel Stride, rebuked ministers for delaying an impact assessment into the change and sending only a short letter half an hour before the vote. If the government does not change course, which No 10 denied it would do, Boris Johnson faces a showdown with peers in the new year over the changes, with several high-profile Conservatives saying they will seek to amend the bill. In the Commons on Monday night, the government narrowly won the vote to change a key aspect of its social care plan that means council contributions to care fees would not go towards the new £86,000 cap. Eighteen Tory MPs voted against the government and 68 were absent. Labour sources told the Guardian that just 13 were paired – meaning they were given official permission to be absent – suggesting dozens of MPs intentionally abstained. A number of abstaining MPs told the Guardian there was widespread discontent at the lack of information over the change to funding, which would hit poorer households in areas with lower house prices, and said dozens more could rebel if the government does not provide more information on how to mitigate the impact. “We didn’t need to rush this through,” a former minister said. “A lot of colleagues are saying now: we’ll look at the full picture and then have a go at amending it again when it comes back from the Lords. “Many of us withheld support because frankly we are sick of being marched up the hill and left behind when the government changes its mind. So we are waiting for that rather than being made to look foolish. The government may well compromise.” Jeremy Hunt, the chair of the Commons health select committee, abstained in the vote and predicted a government U-turn. “I was conflicted, I actually ended up abstaining because it is a big disappointment that they changed the way the cap is calculated,” he told the BBC. He said he expected the government to look again at the plans. The change means homeowners in the poorest areas of England face losing a three times greater share of their housing wealth to pay for social care than people in the most affluent areas, according to Guardian analysis. Johnson sought to reassure ministers at cabinet on Tuesday that “no one will be forced to sell a home they or their spouse is living in as it will not be counted as an asset”. Later on Tuesday Stride said he was alarmed the government was further delaying its impact assessment on the change. In a letter to Stride on Monday night, the health secretary, Sajid Javid, said he could not provide regional or individual assessments on the impact of the change, as the funding at a local authority level has not yet been agreed. “The letter, which was sent half an hour before parliament was set to vote on the changes last night, does not provide the full assessment requested,” Stride said. “I have real concerns about the way these changes have been introduced.” Several influential Conservative peers including Andrew Lansley, another former Tory health secretary, and Ros Altmann, the government’s former pensions adviser, have said they will attempt to amend the bill and send it back to the Commons – though this is not expected until March next year. Labour’s leader in the Lords, Angela Smith, said there could be a buildup of public anger by that time. “In this case, you had something that’s pretty much sneaked out, and then voted on very quickly. And I suspect you’re seeing now those discussions and debates particularly [among] those Conservative MPs who voted for it. Are people thinking – hang on, what does this mean for me?”