Both matches were due to be played on Sunday at 12.30pm but were postponed following requests from Leeds and Watford.

The Premier League board met on Thursday morning and agreed to the requests that were made by both of the visiting sides for the affected games.

A Premier League statement read: "Following postponement requests from Leeds United and Watford FC as a result of COVID-19, the Premier League board met this morning and regrettably agreed to call off the two affected clubs' Boxing Day fixtures. The two games are Wolverhampton Wanderers versus Watford FC and Liverpool FC against Leeds United, both due to be played on Sunday at 12:30pm.

• Latest updates as Boxing Day PL & EFL games fall to Covid
• Premier League, EFL decide against circuit breaker
• 16 per cent of PL players unvaccinated

"The board today was able to make its decisions in advance of Boxing Day to give clarity to clubs and their supporters. We apologise for the inconvenience and disruption caused to those fans' festive plans.

"The league is aware that the decision to postpone these two matches will disappoint supporters and understands their frustrations at a special time of year when fans look forward to attending and watching football games. The league aims to provide as much clarity as possible, but unfortunately postponements sometimes have to be made at short notice, as safety is the priority. The league will endeavour to keep supporters updated if games become at risk on a matchday.

"The board concluded that Leeds United will not be able to fulfil their fixture this weekend due to the number of players with COVID-19, injuries and illness. The club's training ground has also been closed after consultation with the UK Health Security Agency and the Premier League.

"Watford FC continue to have an insufficient number of players to field a team after their game against Crystal Palace FC last Saturday was postponed following a COVID-19 outbreak. Due to players coming out of isolation, it is fully expected Watford will be available for their fixture on Tuesday 28 December, against West Ham United.

"The board assesses applications to postpone matches on a case-by-case basis, based on existing rules and adapted COVID-19 postponement guidance introduced to clubs in light of the new Omicron variant. The board will assess a number of factors, including the ability of a club to field a team; the status, severity and potential impact of the COVID-19 outbreak at the club; and the ability of the players to safely prepare for and play the match.

"The board must also consider the wider risks to the opposition and other people the club representatives may come into contact with.

"While recognising a number of clubs are experiencing COVID-19 outbreaks, it is the clubs' and the league's collective intention to continue the current fixture schedule where safely possible.

"The health and wellbeing of all concerned remains our priority and the league will continue to monitor and reflect public health guidance, always proceeding with caution. In light of the recent rise in COVID-19 cases across the country, the Premier League has reintroduced Emergency Measures. These include protocols such as more frequent testing, wearing face coverings while indoors, observing social distancing and limiting treatment time."

Postponements are not limited to the Premier League, with Preston's game with Sheffield United in the Championship the latest in a growing line of EFL games to fall.

What are the Premier League rules around postponements?

The 2021/22 Premier League handbook includes Covid protocols, and states the Premier League's board will "only permit the rearrangement or postponement of a league match in exceptional circumstances".

The board make calls on a case-by-case basis, and by way of guidance the Premier League says permission for a postponement will not be granted if a club have 14 or more players from their squad list available.

Which Premier League games have been called off?

Brighton vs Tottenham - Sunday December 12, Premier League

Brentford vs Man Utd - Tuesday December 14, Premier League

Burnley vs Watford - Wednesday December 15, Premier League

Leicester vs Tottenham - Thursday December 16, Premier League

Man Utd vs Brighton - Saturday December 18, Premier League

Southampton vs Brentford - Saturday December 18, Premier League

Watford vs Crystal Palace - Saturday December 18, Premier League

West Ham vs Norwich - Saturday December 18, Premier League

Aston Villa vs Burnley - Saturday December 18, Premier League

Everton vs Leicester - Sunday December 19, Premier League

Liverpool vs Leeds - Sunday December 26, Premier League

Wolves vs Watford - Sunday December 26, Premier League

SPFL chief: We cannot delay any more games

SPFL chief executive Neil Doncaster has warned there is no more room to manoeuvre after the winter break was brought forward in light of new restrictions for sporting events in Scotland.

Ten of the 12 Premiership clubs had voted in favour of starting the winter break immediately after the Scottish Government limited crowds at outdoor events to 500 for a period of up to three weeks.

• 500-person limit for Scottish sporting events from Boxing Day
• All SPFL players to have daily Covid tests

However, that proposal was ruled out by the Scottish Professional Football League board as there was simply not enough space in an already congested fixture calendar.

Instead, Boxing Day games will go ahead as planned in front of limited crowds with the fixtures from December 29 and January 2-3 put back to January 17-18 and February 1-2 respectively.

Although Doncaster was pleased a compromise was able to be reached, he issued a warning that should restrictions be extended clubs would have to prepare for the prospect of playing further games with limited crowds.

"It's been a bad week for Scottish football in terms of the restrictions but a good week in terms of the democratic process and the league being able to respond to clubs' requests," Doncaster told Sky Sports News.

"There was an overwhelming view there should be postponements with the majority of clubs wanting to postpone all three festive fixtures. But we only have two available slots prior to the league split so the compromise of playing on Boxing Day but postponing the December 29 and New Year's games was the right approach to take.

"We know it causes difficulties with congestion but the responsible thing from the Board was to listen to the majority and respond. I'm pleased with the compromise put forward, but it now means there's no further room to delay games - we've used the two available slots that exist and there simply isn't any more space."