Those MP want to oust him before he can oust them. The results of this referendum provide the necessary argument for the party leadership to back different candidates in the next election. Which is likely to come sooner that previously expected.
The blairite wing could tolerate Corbyn as an opposition leader for a couple of years, waiting for him to suffer some setback and them getting rid of him. With the resignation of the government and the conflict among the Tories the likelihood of a general election is now high - meaning that Corbyn suddenly became a threat to these MP. The knives are out.
Innonimatu, you continue to astonish me. You have more insight
into UK politics than very nearly all the UK citizens who post here.
An early election is indeed quite likely.
For this the:
"I will implement Brexit" candidates
may be facing the:
"I will not be hasty on Brexit" candidates
and the campaign may only partially be on
traditional Conservative/Labour lines.
Jeremy Corbyn was always a strong euro-sceptic, and could only justify being
pro EU by saying he was in favour of a different EU, a pro-social justice EU .
Now he can say that the people have spoken, and suggest that local Labour
party members should only select "I will implement Brexit" candidates.
Rather than admit that being pro EU was a mistake, the inflexible
pro EU Blairites in their panic turn like Brutus upon Caesar.
The irony is that Jeremy Corbyn is being true to his old guru,
Tony Benn, while Hilary Benn betrays his father's beliefs.