Cabinet ministers have begun rallying around the Downing Street chief of staff, Sue Gray, saying the briefing against her is “appalling” and risks undermining the whole government.

In an attempt to put an end to a series of damaging rows, Keir Starmer denied he had lost grip of his team and insisted he was “completely in control” of his No 10 operation.

Several senior ministers defended Gray after a series of briefings about her pay and her apparently acrimonious relationships with senior colleagues.

Ministers told the Guardian the briefing against her “has to stop”.

Other allies said the role was always the “lightning rod” for discontent within government but that Gray just wanted to get on with the job.

Their intervention follows the revelation by the BBC that Gray had been given a salary of £170,000 – more than Starmer – angering more junior Labour colleagues who had taken a pay cut on entering government.

Starmer is already under scrutiny over his acceptance of more than £100,000 of freebies and gifts over the last parliament. He faces further questions about whether his £35,000 of free tickets from football clubs risks a conflict of interest as the government prepares to bring in a new regulator opposed by the industry.

In a series of local radio interviews on Thursday, Starmer was asked whether he had lost control over his senior team as a result of the pay row, which follows weeks of briefings over power struggles within No 10.

“I’m completely in control. I’m focused and every day the message from me is the same, which is: we have to deliver. We were elected on a big mandate to deliver change, I am determined we are going to do that,” he told BBC South East.

“Look, I’ve got a team here at No 10 and around the cabinet table who are utterly determined and focused on the change that we were elected to bring about.”

The prime minister added that he was “not going to get into” discussions about individual staff salaries, adding: “I’m sure you wouldn’t expect me to.”

Senior officials have, in recent weeks, accused Gray of “hoarding power” and creating a “bottleneck” on decisions, which they claimed were left to pile up on her desk.

Others, however, have said she was prioritising what reached the prime minister’s desk, and carving out time for him to do his job, which, since taking office, has included handling the riots, preparing for the budget and travelling to meet global leaders.

One cabinet minster told the Guardian: “Fundamentally, Sue is good at her job. She’s not perfect, no one is, but she’s strategic, good to work with, will give you a considered view and makes decisions. The briefing is appalling and has to stop. It doesn’t just undermine Sue but the whole government.”

A second said: “Sue is a serious person, doing a serious job very effectively for the government. She’s naturally a team player who raises everyone’s standards around her.”

A third cabinet minister said: “Sue has been absolutely vital for us as a new government coming in and helping to make things happen. Her advice, guidance and knowledge of how to make an impact in government is invaluable.”

And a fourth added: “Those of us who see her up close know the experience she brings. Most of us haven’t served in government before, and value her advice.”

One No 10 insider, who is an ally of Gray, said: “We wouldn’t have been able to get legislation through or put the architecture of government in place so fast without her.”

The disclosure of her salary has triggered a backlash among Labour advisers who said they were furious because she had “micro-managed” their own pay and granted lower sums than their Tory predecessors.

The business secretary, Jonathan Reynolds, denied suggestions that the prime minister had personally intervened to increase Gray’s pay, adding that leaks were “a permanent frustration”.

“There’s a process that exists, it’s a civil service process, it hasn’t changed,” he said. “It’s wrong to say there’s any kind of political input in there or people set their own pay bands.”

The Cabinet Office has said decisions on the pay of special advisers are made by officials, not political appointees, who cannot authorise expenditure of public funds. It has also denied a claim that Gray declined to take a few thousand pounds less than Starmer which may have helped to avoid difficult questions over the decision.

Some government insiders are despairing over the potential damage being done to the government by the briefing against Gray, who has been the subject of a series of reports about fractious relationships at the heart of government, including with Morgan McSweeney, Starmer’s closest political aide.

“It’s definitely damaging, that’s presumably the point of it, but those behind it don’t seem to care about the collateral damage to the PM and the government,” one cabinet source said.

A government insider added: “It’s not about whether they’ve followed the processes on this. It’s about how it looks to the public that they’re all rowing over how much Sue gets paid. People had enough of internal warfare with the Tories.”