Rumour has it that Grahame Morris is considering resigning over Ed Miliband's refusal to back the strikes tomorrow.
Although currently unconfirmed, the PPS to shadow climage change secretary Meg Hillier is said to be dismayed by the Labour leader's statement on the strikes yesterday.
He supposedly views Ed Miliband's position as pandering to the right of the party.
Sources close to Morris say that they are trying to talk him out of it before midday, but he is apparently "very close" to resigning as PPS.
Last night, Ed Miliband condemned the strikes, calling for both sides to "think again".
"Strikes are a sign of failure on both sides and Thursday's industrial action is a mistake," he said.
"I understand why teachers are so angry with the government. But I urge them to think about whether causing disruption in the classroom will help people understand their arguments. You do not win public backing about pensions by inconveniencing the public – especially not while negotiations are ongoing."
UPDATE: After almost a week of deliberation, it was confirmed that Morris was "back on board". Will fill in with more details about his 'hiccup' if I get them.