Clashes between powerful figures inside Downing Street and special advisers are nothing new. Dominic Cummings – Boris Johnson’s right-hand man inside No 10 – had several high-profile bust-ups with spads, as they’re known, which even led to the departure of a cabinet minister.

Theresa May’s pugilistic chiefs of staff Nick Timothy and Fiona Hill became known for their confrontational style. Hill, in particular, made herself unpopular with ministers, Tory MPs and advisers alike with her blunt text messages.

It is, though, unprecedented for the entire spad cadre to feel so aggrieved over how they believe they’re being treated that they come together to take a stand. Yet last month, many of Labour’s spads were revealed to have joined a union over concerns about their pay.

They used their contacts in the media to complain not just about their own situation – with many offered salaries lower than those of their Tory predecessors, and temporary contracts – but also what they perceived to be a lack of understanding in No 10 of the political side of the operation.

Fairly or otherwise, the finger of blame was pointed at Sue Gray, Keir Starmer’s former chief of staff, who had also become the target of criticism over blocking access to the prime minister and holding up decisions.

“We were really angry over the lack of transparency over pay. There was so much pettiness,” one spad told the Guardian. “There was no reason for not telling us pay scales or what Tory advisers had got – we had to find out from officials. It put everybody’s backs up from the get go.”

Another said: “The fundamental issue is that Sue Gray did not value the contribution that political advisers make. We can talk about pay and all of that but ultimately this is about the value at which those jobs were regarded.”

Last weekend, it all came to a head. Starmer, having been warned by senior aides and cabinet ministers that he had to “get a grip” on the No 10 operation or risk internal power struggles undermining the government, asked Gray to step aside.

His top political aide, Morgan McSweeney, was given the role in her place. He had worked alongside many spads in opposition and at the coalface of the election campaign, and many felt that he was one of them. No 10 hoped his appointment would mean the spad rebellion would be over.

It was no surprise, then, that more than 50 special advisers and Labour officials crowded into a committee room in the House of Commons on Tuesday night to listen to the man who had just taken over as No 10 chief of staff.

The weekly meeting, known as “Spad school” under the Conservatives, was McSweeney’s first opportunity to address the whole group about their grievances since Gray was ousted. He was greeted with warm applause.

“He told us this will be sorted, I’m getting a grip of it and it should never have happened,” one said. “There’s an understanding that it will be sorted very, very quickly.”

Another said: “He gave us an undertaking to address pay and so on. He knows how hard we all worked and acknowledged that things should have been better when we got here. That’s the first time that has happened.”

Others described his 10-minute speech to aides as a “pep talk” to reignite the sense of camaraderie that had existed during the general election campaign but had been lacking since.

“I don’t think one talk will change everything overnight but it definitely helped,” one said.

Another added: “The genuine feeling is that this has been resolved now and it’s going to get to a better place.”

McSweeney told them he wanted, in his new role, to help the different teams of spads across departments deliver on the government’s priorities. But there was no mention of Gray. Nor were they disciplined for briefing against her.

After he left, the group was addressed by Ellie Reeves, the Labour party chair, as well as Matthew Doyle, the director of communications, who gave them a commitment that the grid – the weekly diary of announcements – would improve.

Afterwards, special advisers told the Guardian they felt reassured their concerns would be dealt with. “It’s night and day. We’re much more optimistic. There’s a sense that everybody is pulling in the right direction now,” one said.

“This is about the strategic direction of the government and how it functions. Our mood reflected dismay at how Sue Gray had done things without due attention being given to the political side of things.”

Even Starmer is feeling more upbeat after a particularly difficult few days. One ally said: “Keir seemed very chipper when I saw him this week. He does this sometimes – he has a big clear-out of staff and it cheers him up, but usually only for a couple of months.”

But some in Westminster caution the spads from assuming that all their concerns over pay and contracts will be resolved immediately. The Cabinet Office had already announced a review into pay scales last month.

Peter Cardwell, a former Tory adviser and author of The Secret Life of Special Advisers, said: “It’s easy to agree to a pay review, but it doesn’t mean your pay is going to go up, or that you get what you want.

“At the end of the day the power is with senior figures like McSweeney and the Cabinet Office and the number of spads and overall staffing bill will be factors in this. They’re feeling that things are better and want to see what happens. But will No 10 deliver?”

The former spad, who worked in three different government departments, explained how it was a “weird” role with no real job description and people with vastly different levels of experience, making it harder to have a single pay structure.

“Some are glorified bag handlers and others have very serious input on politics, policy, media, and have their boss’s ear. How do you adjust for pay?” he added.

Senior Whitehall figures also warn there will be no sudden resolution to the conflict. No 10 has agreed in principle to the pay review but is understood still to be haggling over the terms of reference.

“Everyone assumes it will be fixed under Morgan,” one says. “But I suspect they’ll be disappointed.”

Nor should Downing Street be reassured that the spad rebellion is over for good. One adviser said they hoped there would be no more problems. But they added: “Were there to be, a marker has been laid down.”