First minister Vaughan Gething looks set to lose a vote of no confidence in his leadership later, after one of his members said that two colleagues are off sick.
The Conservatives called the Senedd vote after weeks of criticism, including some in Labour, of the donations to Mr Gething’s leadership campaign.
Vikki Howells, the chair of the Labour group of MSs, told Radio Wales Breakfast that two members are currently unwell.
She said Vaughan Gething would not stand down if he lost, saying it was a “gimmick” and it was to the “voting public to decide who is in the Senedd”.
Mr Gething would not resign if he loses, Ms Howells said.
With Labour holding exactly half the seats in the 60 seat Welsh Parliament, it needs every backbencher to support the first minister.
The Conservatives have refused to agree to a pairing arrangement where some of their members would not vote in return for Labour absences.
Their motion could be successful if at least one Labour Senedd member either rebels, abstains or does not take part.