Reuters/Stefan Wermuth
More than 50 frontbench MPs have now resigned their positions since the sacking of Hilary Benn, but the resignation of Glass - the MP for North West Durham in the north east of England - is the most surprising given that she was only given the position after party leader Jeremy Corbyn reshuffled his frontbench on Monday to reflect the resignations over the weekend.
Glass confirmed her resignation in a tweet:
It is with a heavy heart that I have today resigned as Shadow SoS Education. My dream job but the situation is untenable
- Pat Glass (@PatGlassMP) June 29, 2016
Glass's resignation comes as Corbyn faces an increasingly bitter fight with his parliamentary party, which resulted in a "vote of no confidence" against Corbyn on Tuesday.
Corbyn lost the vote by an overwhelming margin, with 172 Labour members of Parliament voting against Corbyn compared with 40 MPs backing him. That represents a majority of over 80% against Corbyn.
The scale of resignations is now so severe that Corbyn is reportedly struggling to find enough MPs to fill his entire Shadow Cabinet, and there are rumours that he and Shadow Chancellor John McDonnell are prepared to fill several roles each.
Regardless of parliamentary opposition to his leadership, Corbyn is refusing to step down, saying that he still maintains a majority of support from the party's supporters. "I was democratically elected leader of our party for a new kind of
Stepping down from the Shadow Cabinet comes just a day after Glass said that she will not be standing for re-election at the next General Election, which could come as soon as this year, should the new Conservative party leader trigger an election when they become prime minister in September.
Glass also confirmed that decision via tweet:
I have informed my CLP Chair that whenever the next General Election takes place, I will not be Labour's candidate. pic.twitter.com/g3DADx57KF
- Pat Glass (@PatGlassMP) June 28, 2016