Senior Tories have privately voiced fears about a slew of concessions made by Rishi Sunak to rebels on planning, the environment and online safety, suggesting counter-rebellions may have to be organised. Several former ministers have suggested they are worried about Sunak’s strategy and said the prime minister could find himself trapped between two wings of his party. Potential flash points include the retained EU law bill, the economic crime bill and the finance bill after the spring budget. One warned that Sunak would risk seeing counter-rebellions emerging that could reignite old party tensions if the same concessions were seen on other issues such as Brexit, taxation or planning. “We cannot have a situation where the prime minister is so frightened of his own party that 30 colleagues can get him to change his mind about anything,” one former cabinet minister said. Another former minister, a supporter of Sunak, said the prime minister was on shaky ground because he derived his mandate from Conservative MPs, rather than the party or from the electorate. “Losing a vote is effectively a confidence thing,” they said. “Relying on Labour votes to push anything through starts to raise all sorts of questions.” On Monday Sunak caved into demands from Tory rebels who had signed an amendment to the online harms bill that social media bosses could face criminal charges and even jail over content on their platforms. “It is genuinely bonkers,” one former minister said of the change. Sunak, however, was risking potential defeat because Labour had backed the change to the bill, which is to be tabled when it reaches the House of Lords. The levelling up secretary, Michael Gove, made two significant concessions to rebels last year – including relaxing regulations on onshore wind in a rebellion that was also backed by Labour. But the other concession was to drop mandatory building targets after a rebellion was threatened by at least 50 Conservative MPs, despite Labour saying it would not back the amendment. The Guardian revealed this week that thousands of new homes are at risk after a series of local authorities cut or delayed their housebuilding plans after the decision. Some experienced Conservative MPs said Sunak had exposed a potentially fatal weakness by not facing down the group. “I think there are a number of us who regret not mounting a counter-rebellion on that issue,” one said. Another former minister also said future rebellions from opposing wings of the party were on the cards, especially on contentious issues such as planning and taxation. Key figures from Liz Truss’s cabinet have also formed a pressure group called the Conservative Growth Group, including the former levelling up secretary Simon Clarke, the ex-environment secretary Ranil Jayawardena, and the former DWP secretary Chloe Smith. The group formally launched on Wednesday night with an intention to keep up the pressure on the government on low taxes but also on pro-growth supply side reforms, including deregulation of planning, childcare and business regulations.