Yesterday she announced she would stand down from the post at a General Election, but her departure was hastened.
Ms Glass tweeted, ‘My dream job but the situation is untenable.’
Amid a time of post Brexit political uncertainty, the early years sector had on Monday welcomed the news of her appointment, because of her long career in education.
On the same day, Jenny Chapman MP, who replaced Ms Glass as shadow childcare minister when she became Europe minister in January this year, also resigned from the Labour front bench on the same day.
The latest revelation came after Labour leader Jeremy Corbyn yesterday lost a MPs' vote of no confidence.
Neil Leitch, chief executive of the Pre-school Learning Alliance, today described the lack of both a shadow education secretary and an early years minister as 'untenable'.
Mr Leitch said, ‘We are sorry to see Pat Glass leave the post of shadow education secretary so soon after her appointment.
'As someone with a wealth of experience in childcare and education, we would have welcomed her input into the early years debate. That said, we of course understand and respect her reasons for taking this decision.
‘It is, however, very concerning that there is currently no shadow education secretary or shadow childcare minister.
‘With the rollout of the 30-hour free entitlement offer drawing ever closer, and the pilot scheme due to begin in a matter of months, it is vital that parties from across the political spectrum are involved in the development and scrutiny of this policy; however, as it stands, this is not possible.
‘This is not a tenable situation and we hope that the Labour party will look to rectify this situation as a matter of urgency.'
Ms Glass had been among the MPs at the first meeting of the new Shadow Cabinet, cobbled together after Mr Corbyn haemorrhaged frontbenchers.
A former Labour councillor in the north-east, Ms Glass has held senior positions in local education authorities across the country.
She advised the Government on education policy, and with expertise in special needs, she worked with councils to improve education across the Yorkshire Humber region.
Following her election as MP for North West Durham in 2010, Ms Glass became lead opposition member on the Education Select Committee.
She was initially appointed shadow education minister covering childcare and early years, in September 2015, when Mr Corbyn first formed his shadow cabinet.