The operator, which employs some 44,000 workers, said it was unable to confirm any numbers at present and put the redundancies down to the latest Government restrictions.
A spokesperson for M&B said: “Our industry is operating in exceptionally challenging and uncertain circumstances.
“While we have worked incredibly hard to make sites Covid-19 secure and keep staff and customers safe, we are facing significant difficulties from the recently introduced 10pm curfew for pubs, bars and restaurants, new enforced closures and tapering Government support that doesn’t go far enough."
The spokesperson added: “M&B, like many others in the sector, has taken the very difficult and regrettable decision to open redundancy consultations with a number of our front line team and will seek to redeploy affected staff wherever possible.
“With trading restrictions and uncertainty likely to continue for the foreseeable future, we strongly urge the Government to step up the level of support it is offering to an industry that has been repeatedly singled out and taken the full brunt of restrictions.
“We have opened consultations today (Tuesday 13 October) and will seek to redeploy affected staff wherever possible. We are unable to confirm numbers at this time.”
M&B is the latest pub company to announce job losses as Greene King recently revealed it was preparing to close 79 venues and cut hundreds of jobs due to a drop in trade.
The closures equate to about 2.5% of Greene King’s 3,100-strong estate and the 800 potential job losses is around 2.1% of its 38,000 employees.
The Morning Advertiser understands while 800 of Greene King's members are impacted by the closures, the company is looking to redeploy them in other parts of the business.
Meanwhile in September, pub staff at JD Wetherspoon (JDW)'s airport sites were told a possible 400 to 450 roles are at risk of redundancy due to a drop in passenger numbers, it has announced.