At least 30 Labour MPs including several frontbenchers are set to defy Jeremy Corbyn tonight and vote against article 50.

Serving shadow ministers, such as Rosena Allin-Khan and Rupa Huq, as well as two who recently resigned over the three-line whip, will vote against the Brexit bill when two days of debate concludes today.

Kevin Brennan, the shadow culture secretary, has also confirmed he will vote against after “listening” to the debate in the house.

In an almost unprecedented turn of events, some of Labour’s own whips are also expected to vote against the move after Vicky Foxcroft, Jeff Smith and Thangam Debbonaire confirmed their stance in recent days.

So far only Jo Stevens and Tulip Siddiq have quit the frontbench over article 50. It could become clearer tonight whether more MPs intend to quit shadow ministerial positions while Corbyn has tried to strike a tough stance towards the shadow cabinet, saying on Sunday week it would be “impossible” for members of his top team to remain in post if they rebelled.

With the Commons set to vote on the government’s short Brexit bill, some time before 7pm, several Labour MPs have confirmed their stance in the last 24 hours.

Lyn Brown and Huq, both shadow home office ministers, as well as Stephen Timms, a former shadow cabinet minister, said they would vote against article 50.

Today Ian Murray, the former shadow Scotland secretary, told constituents he would be “standing up for them in the Commons” by voting against the bill.

The MPs set to vote against article 50.