Allies of Boris Johnson have been accused of preparing to block a motion to suspend the disgraced Scottish MP Margaret Ferrier, leading the government to postpone the vote in parliament. It is believed that supporters of the former prime minister feared that a vote to suspend Ferrier for 30 days over a breach of Covid-19 rules could set a precedent if Johnson faced a similar vote. No reason was given for the last-minute postponement on Thursday in which the deputy speaker was notified that the government had “not moved” a motion to allow MPs to decide on a recommendation by the committee on standards regarding Ferrier’s suspension. Chris Bryant, the committee’s chair, said the government had suddenly got cold feet over allowing the vote because supporters of Johnson believed he would face a similar sanction. “The government apparently suddenly heard that Boris Johnson supporters were going to vote down the motion. So they suddenly pulled it. I’m afraid all this shenanigans does is bring the House of Commons further into disrepute,” he told the Guardian. “It just feels as if there are some people who just don’t want to uphold standards in public life and the government hasn’t got the willpower or the ability to enforce discipline,” said Bryant. Government sources said the vote needed to take place when the house had a sufficient quorum of MPs and would therefore be scheduled after the “Whitsun” recess, which ends on 5 June. However, Bryant dismissed this, saying that Labour had told the government that there were plenty of MPs to vote it through on Thursday. The shadow Scottish secretary, Ian Murray, alleged that the postponement was the result of an “unholy alliance” involving the Tories, the SNP and Ferrier – a former SNP MP who now sits as an independent. “A grubby backroom deal between Ferrier, nationalists and some Tories, who don’t want Boris Johnson to suffer the same fate, has prevented the democratic process from taking place,” he said. On Monday, Ferrier lost her appeal against the proposed 30-day ban from the House of Commons over Covid rule breaches, paving the way for a byelection in the MP’s Scottish constituency. The former Scottish National party MP was found to have damaged the reputation of the Commons and put people at risk after taking part in a Commons debate and travelling by train while she had Covid in September 2020. The failure of her appeal could trigger a recall petition in her Rutherglen and Hamilton West constituency, where a byelection would provide Labour with an opportunity to contest a seat in Scotland, where it hopes to make gains in the general election. The length of Ferrier’s suspension alarmed backers of Johnson, who is being investigated by the privileges committee about breaches of Covid rules in Downing Street. He hopes to avoid a similar lengthy sanction, which may prompt a byelection in his Uxbridge seat.