Julian Lewis, the new chair of parliament’s intelligence and security committee (ISC), has demanded that ministers prevent Dominic Cummings and other special advisers from politicising its future inquiries. The independent MP told a Commons debate on the Russia report on Wednesday that he had been warned by a journalist that “some people within government” had tried to sack the committee’s civil service secretariat and “make political appointments” instead. Lewis then called on James Brokenshire, the security minister, to give “a categorical commitment that no party political special advisers will be allowed anywhere near the intelligence and security committee”. Brokenshire responded by giving a non-committal answer – “he can certainly have my assurances to the weight and the support that I give to his committee” – prompting a string of concerned MPs to repeat Lewis’s question. That culminated in Yvette Cooper, the Labour chair of the home affairs select committee, asking Brokenshire to “rule out any attempt at government interference in the work of the ISC, any political appointments to its secretariat.” Brokenshire said he was “very clear on the need for independence by the ISC” and added: “Certainly I do not want to see the sense of that question of its independence being drawn into any doubt.” Concerns about the politicisation of the committee – traditionally a cross-party body that oversees the spy agencies – have been in the air for months after Downing Street refused to release the Russia report before last December’s election. It was eventually published on Tuesday and revealed that the British government and intelligence agencies had failed to conduct any proper assessment of Kremlin attempts to interfere with the 2016 Brexit referendum. Nick Thomas-Symonds, the shadow home secretary, accused the government of “a dereliction of duty” by sitting on the report for months and “blocking its publication before a general election”. Labour had secured the emergency debate after the government refused to organise one. The 50-page document, the product of 18 months’ research in the last parliament, revealed how deeply Russia has penetrated British life through a mixture of cyber-threats and the presence of oligarchs who hire London-based advisers and make political donations to reinforce their position. “We categorically reject any suggestion that the UK actively avoided investigating Russia,” Brokenshire said. “We are unafraid to act wherever necessary to protect the UK and our allies from any state threat.” Lewis had the Conservative party whip removed last week after he stood against Downing Street’s preferred choice of chairman, Chris Grayling, and defeated him by five votes to four with the support of Labour and SNP members. Consideration was briefly given to trying to remove the veteran MP from his post, but No 10 relented, leaving him to chair the committee, which traditionally works in a non-party political fashion. Downing Street said it was surprised by Lewis’s comments and it was not immediately aware of what exactly he was referring to. The Labour backbencher Chris Bryant said he believed that the UK had become too easy on wealthy Russians, and he accused the government of being complicit in helping them hide their wealth offshore. “What mystifies me is that government ministers are still giving out golden visas to dodgy Russian oligarchs, that government ministers are still granting exemptions to dodgy Russian oligarchs so that they can hide their ownership of businesses in this country, and I am mystified that government ministers are still taking millions of pounds from dodgy Russian oligarchs,” the MP said. Keir Starmer called on Scotland’s first minister, Nicola Sturgeon, to publicly condemn her SNP predecessor, Alex Salmond, for hosting a show on the Kremlin-backed TV channel RT. Speaking after prime minister’s questions on Wednesday, a spokesman for the Labour leader said: “We completely condemn it and we advise the first minister Nicola Sturgeon to do the same.” The SNP said Sturgeon had already criticised Salmond’s decision when his show was announced in 2017. At the time, she said: “His choice of channel would not have been my choice.” The ISC said in its report that RT broadcast “serious distortions” along with its fellow state-owned broadcaster Sputnik. Salmond is no longer a member of the SNP, having resigned when charged with sexual offences in 2018.