Home Secretary Priti Patel has accused a Tory MP of breaching coronavirus rules by attending a Christmas dinner for 27 guests.

Tobias Ellwood, chairman of the Commons Defence Committee, apologised on Thursday after it emerged he gave a speech at the Cavalry and Guards Club in Piccadilly hours before London entered Tier 3.

The Bournemouth East MP argued the Iraq Britain Business Council event, described on the organisers’ website as a “Christmas party”, was “fully Covid compliant” and he said he attended for business purposes as permitted under Tier 2 rules.

But, in comments backed by Downing Street, his Conservative colleague Ms Patel suggested he could face a fine for his attendance at Tuesday’s event.

I am sorry coverage of my well intentioned attendance may have muddled the Government’s clear message as we head towards Christmas

Asked by ITV News if his actions were an “egregious” breach of the rules, Ms Patel said: “Well, it is. Of course it is exactly that.

“Having dinner outside of the rules with a large number of people is a breach of the regulations.”

Asked if there should be a punishment, Ms Patel said: “There are fixed-penalty notices. I don’t know the details as to where this happened or the location, but I’m sure, as it is a breach, that will be followed up.”

But she declined to say whether it is a disciplinary matter for the party, acknowledging “I simply do not know the full details”.

Asked about Mr Ellwood, the Prime Minister’s official spokesman said: “I would point you to the Home Secretary’s words.

“The PM has been clear throughout the pandemic that it’s vital for everybody to abide by the rules in order to suppress the virus and therefore protect the NHS and save lives.”

In a statement, Mr Ellwood said he “gleaned extremely useful intelligence” about the issues on the ground in the Middle East during the “business reception/dinner”.

He added: “The event took place at the respect Cavalry and Guards Club under strict Covid compliant conditions.

“For the duration of Tier 2 restrictions function rooms that usually seat over 100 have been converted to hold business events for less than 30.

“I appreciate, given the current challenges, some will question the wisdom of my attendance.

“I am sorry coverage of my well intentioned attendance may have muddled the Government’s clear message as we head towards Christmas.

“Whilst the event was fully Covid complaint – perceptions count.”

In an interview with BBC Radio 4’s PM programme, Mr Ellwood insisted “the rules weren’t breached” when asked if he would consider his position as a select committee chairman.

And he suggested the Home Secretary should contact the Cavalry and Guards Club first before deciding whether he should be fined for his actions.

Mr Ellwood attended the event the day after he told the Commons that allowing families to meet over Christmas “could be very dangerous indeed”, and he suggested the relaxation of rules over the festive period could lead to a “third wave”.

The Government’s Tier 2 guidance states “gatherings for work purposes are only allowed where they are reasonably necessary”.

The club’s secretary David Cowdery said: “We don’t comment on private events here at the club.

“The full Covid policy issued by the club was given to the organisers of the event.”

But he declined to comment further when asked if he could guarantee the organisers complied with the policy.