CMA chair Tyrie quits to speak out for reform

The former Conservative MP said he had helped make the CMA more attuned to ordinary consumers and less cumbersome since starting the job in June 2018. He will leave in September.

Tyrie has complained that the CMA's powers are not strong enough and has asked for authority to fine companies without going to court. He has also been strongly critical of concentration of power in a few big technology companies.

The government has sat on one of Tyrie's main recommendations, a shakeup of the audit market, since April 2018. Tyrie called for rapid legislation to split the big accountants' audit and consulting arms but officials are reported to have discussed ditching some of his proposals.

Under Tyrie the CMA ruled out Sainsbury's takeover of Asda and surprised the City with a last-minute inquiry into Takeaway.com's purchase of Just Eat - though it approved the deal in the end. The CMA also clamped down on anticompetitive pricing online, including by the guitar maker Fender.

He has resisted threats to the CMA's independence reported to come from Dominic Cummings, Boris Johnson's adviser, whom Tyrie tangled with as an MP. As chair of the Treasury committee, Tyrie, who opposed Brexit, accused Cummings in 2016 of presenting an "Aladdin's cave" of questionable benefits from leaving the EU.

Tyrie's comments on his departure suggested he was frustrated in his current job and that the government's mood had turned against his push for change under Johnson.

"On taking the role, I was asked by the government to map out a route to a new type of competition authority, one better equipped to understand and respond to what most concerns ordinary consumers," he said.

"I now want to make the case more forcefully for legislative and other reform – in Parliament and beyond – than is possible within the inherent limits of my position as CMA chairman."

Tyrie was appointed when Theresa May was prime minister and Greg Clark, an opponent of Johnson, was business secretary. As an MP he built a reputation as an independent and tireless inquisitor on the Treasury committee before standing down from Parliament in 2017.