Redundancies at Wilko have been put on hold while last-minute rescue bids for the troubled retail chain are considered.

Separately, one interested buyer, M2 Capital, has attacked administrator PwC and questioned whether the process has been “fair and transparent”.

The GMB met with administrators PwC on Tuesday morning after the union called for an urgent meeting with the business secretary.

GMB said PwC had received “multiple bids” to save Wilko and any potential job losses have been suspended while they are mulled over.

GMB national secretary Andy Prendergast said: “Whilst this is a positive development, Wilko is not out of the woods by any means and this is a time of incredible stress and worry for the 12,500 workers who face losing their jobs.”

The union wrote to business secretary Kemi Badenoch on Monday, implying bidders had reported “difficulties” engaging with PwC. GMB asked Badenoch for reassurance that “all steps will be taken to protect jobs as part of this process”.

A government spokesperson said: “While this is a commercial decision for the company, we understand that this will be a concerning time for workers at Wilko.”

The spokesperson added that the government would “continue to stand firmly behind business” having provided support with VAT cuts and business rates holidays.

Wilko collapsed into administration earlier this month putting 400 stores and over 12,000 jobs at risk.

The chair of M2 criticised the bidding process in an email to PwC’s chair, the Financial Times reported. He said M2 had submitted an offer of more than $100m for Wilko but criticised the timing of deadlines and lack of access to a data room.

A source close to the process told the newspaper there were questions over the seriousness of M2’s offer and whether it had the required funds available.

Several bids to rescue the business have been proposed, including from fellow value retailers B&M and Poundland, as well as HMV owner Doug Putman.