One of Jeremy Corbyn’s inner circle, after a day spent anxiously watching Labour’s national executive committee and becoming more and more gloomy, sent out a text message on hearing he would automatically be on the ballot. “Phew,” it read.

That sense of relief quickly gave way to celebration. The national executive vote is effectively the last act in the parliamentary Labour party’s bungled coup attempt, the last chance to remove him.

Among those celebrating was Sam Tarry, who is on the steering committee of Momentum, the organisation set up in the autumn to support Corbyn. “The coup has completely failed. It was a disaster from the start. We have dropped massively in the polls and that is because of the parliamentary Labour party.

“I think there is going to be a day of reckoning for them.”

Some MPs could face retribution in the form of votes of no confidence by their constituency Labour parties, possibly leading to attempts at deselection.

Corbyn starts as favourite to win the leadership contest and, having survived the national executive vote, he can consolidate his hold, making further coup attempts even harder, if not impossible. There are six places on the national executive to be be voted on by all party members this summer, and the pro-Corbyn slate has a good chance of taking at least some – if not all – of them.

At the annual party conference in Liverpool in September, the Transport Salaried Staffs’ Association is to put forward a resolution to drop the bar for a leadership bid from 20% support of MPs to 10%, which Corbyn would easily achieve. The group Grassroots Labour is to put forward a resolution to drop it even further, to 5%.

The parliamentary Labour party could mount a legal challenge to the national executive ruling but it is unlikely to succeed and taking a party matter to court would only further anger many grassroots members.

Since the coup attempt two weeks ago, Labour membership has jumped by more than 100,000, according the party officials. It stood at 388,000 in January and is now estimated at more than 500,000.

Saving Labour, the anti-Corbyn organisation, claims many of these new members are opposed to him. Pro-Corbyn groups such as Momentum claim most of them are Corbyn supporters, part of a backlash against the parliamentary Labour party’s coup attempt.

In Wallasey, the constituency of Angela Eagle, where membership has jumped from 900 to 1,200, anecdotal evidence suggests at least some of these – and perhaps even most – are pro-Corbyn.

Kevin Hall, a train driver from Wallasey, said he joined up with three friends a fortnight ago to vote for Corbyn: “I saw what was going on. The parliamentary Labour party was trying to undermine him. They said he had lost the support of the parliamentary Labour party but he had never had it. The coup has backfired.”

He is hoping to be present at the next meeting of the Wallasey constituency Labour party on Friday 22 July, where Eagle will face her members for the first time since the coup attempt and the launch of her leadership challenge.

Hall, 48, who said he had never been a member of a party before, said he spent Tuesday following events at the national executive on Twitter. He has no internet access in his flat and had to stand outside a restaurant with Wi-Fi to follow events. “I was absolutely delighted. I was messaging friends. I had been quite worried,” he said.

In spite of the euphoria expressed by Hall, there are widespread misgivings about Corbyn that might make reelection harder. On doorsteps in Labour areas – never mind in Conservative-held seats – a common refrain among Labour voters is that they do not think he can win a general election.

Councillor Ged Taylor, who represents the Knotty Ash ward on Liverpool city council, is glad Corbyn is on the ballot, regarding this as the just thing to do. In spite of this, he described the national executive vote as “a suicide vote” because he does not believe Corbyn can win a general election and predicts a catastrophic result.

But he is critical of the parliamentary Labour party, too. “The coup was badly timed and clumsy. They panicked because they thought there was going to be a snap election.”