Candidates for the roles of Labour leader and deputy leader reacted with disbelief after being told they all had to pre-record their own victory statements before the result is announced next weekend.

The name of the next Labour leader and deputy leader will be revealed at 10.45am on Saturday in an emailed press release from the party, after plans for a grand coronation were abandoned as a result of the coronavirus crisis.

Under plans hammered out by the party over recent days, the outcome of the three-month contest will be emailed to the media, and more than 500,000 party members who were eligible to vote, with a link to a recorded acceptance speech by the winner.

It emerged, however, that all three candidates for leader – Keir Starmer, Rebecca Long-Bailey and Lisa Nandy – and the five contesting the role of deputy had all been asked to record speeches by this Wednesday, as if they had just heard they had won.

One of those in the contest told the Observer: “The first thing they wanted to do was announce it with us all in a Zoom call which was never going to work.

“Then they came up with the idea of us all recording victory speeches in advance which is just completely ridiculous. It is like the X Factor. Imagine what would happen if any one of these recordings got into the public domain, with us laying out our plans for the future and saying how wonderful it felt to have won. The unrealistic nature of it all just about sums up the last five years.”

Another candidate said: “It is impossible to see how anyone can record something in advance like this with any conviction. It is not going to happen.”

It is now expected that some other method will be found so that brief acceptance speeches can be made on the day of the announcement by the two winners.

Under the current plans the candidates to succeed outgoing leader Jeremy Corbyn and his former deputy Tom Watson will be informed of the result a few minutes before it is made public.

The deputy leadership is being contested by Angela Rayner, Rosena Allin-Khan, Richard Burgon, Ian Murray and Dawn Butler.

The original plan had to been to gather at least 1,000 party members and senior figures at a special conference in London to announce the new leader.

Starmer is the bookies’ favourite to win the contest for leader while Angela Rayner is regarded by many as frontrunner for the deputy post. On Friday Rayner announced she was “self-isolating” after suffering symptoms of coronavirus.

She said on Twitter: “I am now in self isolation as I have the symptoms of #Coronavirus they started last night and have gradually got worse. I will be a bit quieter than usual but will still be keeping in touch with people as best as l can.”

In an interview with the BBC’s Political Editor Laura Kuenssberg on Friday, Corbyn said the country had been “ill-prepared” for the coronavirus pandemic because of “10 years of austerity, of underfunding the National Health Service and underfunding our benefit system”.