OXFORDSHIRE will not be subject to new 'tier 4' restrictions as the Prime Minister announced new measures tonight but the Christmas relaxation rules have been tightened.

In a Downing Street briefing held tonight Boris Johnson said that all areas in London, the East and the South East currently in tier 3 will move into a stricter tier 4.

The county was not among those which were placed into tier 3 just days earlier and remains in the relatively relaxed tier 2.

The previously agreed relaxation of the rules over Christmas, however, will now be changed across the whole of England.

Mr Johnson said: "It's with a very heavy heart we can't continue with Christmas as planned.

"In England those living in tier 4 should not mix with anyone outside their own household at Christmas."

He added that across the rest of the country the rules allowing three households to mix will be limited to Christmas Day only, instead of over five days.

He said: "I know how much emotion people invest at this time of year and how important it is for instance for grandparents to see their grandchildren, for families to be together.

"So I know how disappointing this will be but we have said throughout this pandemic that we must and we will be guided by the science.

"When the science changes we must change our response.

"When the virus changes its method of attack we must change our method of defence.

"As your Prime Minister I sincerely believe there is no alternative open to me."

In his address Mr Johnson said the measures had been introduced because of the emergence of a new strain of the virus.

The tier changes, with neighbouring Buckinghamshire and Berkshire affected, will come into force from tomorrow.