As Theresa May coughed and spluttered through her ill-fated party conference speech on Wednesday the home secretary, Amber Rudd, tried to ride to her rescue. Clearly aware that cough sweets and glasses of water were failing to do the trick, Rudd was desperate to buy the prime minister some breathing space. “Give her time,” she told the chancellor Philip Hammond and foreign secretary Boris Johnson as she urged the cabinet’s front row to its feet for another lengthy standing ovation.

While there was sympathy in abundance for the prime minister in the hall, it had taken a terrible coincidence of disasters – the cough, a prankster and a disintegrating stage set – to stir such generous feelings. The Tories had gathered in Manchester desperately depressed, deeply divided, angry at May and in smaller numbers than normal. “It is a ghost conference,” said one senior MP on the opening day. “I have never known such a haunted feel about the place and such a lack of discipline.”

In the conference bars and cafes, ministers, MPs and delegates spent the week debating whether their leader should be allowed to carry on. Few made any effort to defend May. Many were still fuming about the snap general election she took them into with disastrous consequences, and all were deeply worried about the prospect of a Jeremy Corbyn government. Most had no enthusiasm for a Johnson succession – but few thought the prime minister could survive for long. “We are royally screwed and need a total, complete and utter revamp,” said one senior MP. “Our problem is that to revamp you need a new leader, but we have no idea how we get one without causing complete mayhem and splitting the party even more. That’s the issue in a nutshell.” Both sides of the party’s Brexit divide fear that a leadership contest could deliver a successor of the wrong Brexit persuasion, sow yet more division and increase the chances of letting in the dreaded Corbyn. Among a growing number of MPs and party donors there is a sense that the minimum required is a reshuffle giving cabinet power and influence to a younger generation. If the party cannot at the moment regain its lost momentum, at least it could literally rejuvenate.

Cabinet ministers offloaded their frustrations in private at every opportunity, blaming May and her former advisers – Nick Timothy and Fiona Hill, who were both sacked two days after the election – for what one described as a “shockingly bad” election campaign in which their advice had been ignored and political suicide committed. Those scores have yet to be settled. Johnson was the object of much vitriol for so brazenly positioning for the leadership, but criticism of May was just as visceral. A former minister said the party’s election manifesto offering on social care had read “like it had been written by Alan B’Stard”. Another ex-minister said it was impossible to rally enthusiastically behind the prime minister, partly because people still felt so resentful at the way she and her advisers had treated them when she was all-powerful. One minister said: “It is difficult just to forgive and forget all that and be all sweetness and light.” The past five months had also left huge questions about May’s judgment. “It is just not sustainable for us to renew under someone who led us into this mess,” said another minister.

Boris Johnson angered many Tories by brazenly positioning himself to succeed Theresa May. Photograph: Christopher Furlong/Getty Images

This was the backdrop of bloodletting against which May began her speech on Wednesday – one which was supposed to rescue her premiership. For weeks she and her advisers had been fine-tuning the content, in the hope that it would allow her to soldier on at least until after Brexit. They knew that party activists wanted to hear a direct apology for the election and the way it backfired. On that she gave them what they wanted – a full mea culpa. They also knew that with Corbyn’s Labour attracting more and more youthful support she had to at least begin to show the Tories cared about a section of the electorate they had all but lost. Announcements on building more houses and tuition fees costing many billions of pounds were hurriedly put together.

But even this appeared to some Tories as too reactive, as signals of her lack of ideological backbone and a willingness to throw overboard Conservative principles which many in the party hold dear. Writing on ConservativeHome, the website’s editor, Paul Goodman, a former MP, said: “The key problem with the speech was that for all its content it lacked clarity – and so failed to point a coherent way ahead either for the Conservatives or, especially, for May herself. You cannot adapt to the Corbyn challenge by making a stirring defence of free markets … and then carry on as usual by stressing energy price caps and more council houses.” Some donors were annoyed by the content on council housing and energy caps, which they regarded as “Labour-lite” and not Conservative.

As the wave of post-speech sympathy subsided it was not long before the plotting began and small groups of MPs began taking soundings about how to replace her. It was those soundings that are said to have alerted the whips and led to the outing of the ringleader, Grant Shapps. Charles Walker, a member of the executive of the 1922 committee and a May loyalist, said that after being beset by so much bad luck throughout the week, the fact that it was Shapps (an MP he suggested had precious little credibility among his peers) who was identified as the plotter-in-chief showed, perhaps, that May’s luck had turned. After Rudd attempted to calm things with a newspaper article urging loyalty on Friday, Johnson used the Tory MPs’ WhatsApp group to show his support. “Folks I am away but just read all this,” he wrote. “See Amber piece this am. She is right right right. We have JUST HAD AN ELECTION and people are fed up with all this malarkey. Get behind the PM. Ordinary punters I have spoken to thought her speech was good and anyone can have a cold. Circle the wagons turn the fire on Corbyn and talk about nothing except our great policies and what we can do for the country.”

Grant Shapps led a failed attempt to oust the prime minister. Photograph: Paul Ellis/AFP/Getty Images

While the plot to ditch May seemed to run out of steam before it really gained momentum, wise heads said that the whole conference experience had left a deep wound on the prime minister. May was far from home and dry. There are plenty of MPs who still feel she should fall on her sword. Another ex-minister remarked: “Really, she needs to consider her position. It’s looking extremely bad for her. The cabinet have arranged their wagons around her, but what are they protecting? I don’t think anyone thinks she will last to the end of the Brexit process.”

Those who still want to strike quickly believe that if she is allowed to limp on into next year they could be stuck with her into 2019, as it will be impossible to change leader and prime minister as the climax to the Brexit negotiations approaches. If she does go, or if a contest is forced, Johnson and David Davis are seen as the most likely successors. Some of their supporters are urging them to sort out the Tory succession between them. “The best thing they could do is come to an accommodation between themselves,” said one.

As MPs are preparing to return to Westminster after the conference season break, the road ahead for May is littered with political landmines. Labour, sensing blood, stands ready to exploit her weakness and the disunity of her government. Brexit looms largest. Already, following the Tory conference, there are signs that European leaders are losing faith in the prime minister’s ability to endure for long. EU officials and diplomats are warning that the prospect of Brussels making concessions or striking deals in negotiations with someone they believe may not be long for No 10 is not an appealing one. The EU is turning its attention to the distinct possibility of having to negotiate with Corbyn and Labour’s Brexit spokesman Keir Starmer instead. Starmer said that “the single biggest threat to Britain crashing out of the EU with no deal is now Tory infighting”. He added: “If the prime minister is unable – or unwilling – to show leadership on the most crucial issue of our generation, then Labour will.”

This week the latest round of talks begins in Brussels. The prime minister, in her weak state, is unlikely to be able to offer more details on the financial settlement that the UK may be prepared to make. Johnson, Priti Patel, Andrea Leadsom, Liam Fox and Michael Gove all have personal red lines on the shape of Britain’s EU relationship after 2021. The details of how a transition period will work and what follows have yet to be hammered out. Then there is the chancellor’s November budget, in which he will have to find ways to pay for the billions of pounds of extra spending announced on new policies (student fees and housing among them) in the past week. Having promised to do more to help young people find homes, pressure is growing by the day on the chancellor to end the cap on housing benefit, which critics warn is threatening up to a million people with homelessness.

Polling by Opinium for the Observer this weekend shows that the conference season, rather than helping the Conservatives and May, has damaged both, while Labour and Corbyn have gained in credibility. The Tories are now seen as more divided than Labour for the first time since before Corbyn became leader. May’s ratings are on the slide while Corbyn’s are on the rise.

The prime minister survived a terrible week thanks to a wave of sympathy from her party and the public and a failed coup attempt that her whips managed to turn to her advantage. But this week politics resumes in the House of Commons with Labour on May’s case as never before. Tories know she cannot afford another failure.

“We just have to try to get behind her at prime minister’s questions [on Wednesday],” said a member of the backbench 1922 committee . “But there are many problems ahead and no one is pretending it is going to be easy. In fact quite the reverse.”