England's Kane has British PM flying the flag for World Cup matches

England players celebrate a goal against Panama. [Photo/Courtesy]

England's bright start to the World Cup has infected even the normally placid British Prime Minister Theresa May with football fever as she flies the flag for Harry Kane's young team.

After more than half a century of heartache, fans have started to dream that England can emulate the team that won the 1966 World Cup, led by Bobby Moore.

May said England's flag of St George would fly proudly over her official residence at 10 Downing Street on the days the team were playing in Russia and during next year's women's World Cup in France.

May, along with government ministers and members of the royal family, will not attend matches at the World Cup because of Russia's alleged poisoning of a former Kremlin double agent in Britain earlier this year.

England play Belgium on Thursday to decide who will finish top of Group G.

"No 10 will be flying the England flag on the day of each of England's matches from now on," May told Parliament in answer to a question from a lawmaker of her own Conservative party. "We will be encouraging other government departments to do the same.

"I'm going to go further than my predecessors. Next year we will do the same for the women's World Cup."

Opposition leader Jeremy Corbyn -- renowned for being reluctant to display overt patriotism -- has a flag of St George in his office but would not be drawn on whether one would fly from Labour party headquarters.

"Jeremy is a strong football supporter and he is supporting the England team and I'm sure he will find his own way of expressing that," a source was cited as saying by Britain's Press Association.

The flag of St George will perhaps more contentiously be flown from the Scotland office, revealed May's Secretary of State for Scotland David Mundell, who is confident the gesture will be reciprocated come the 2022 World Cup, when he fully expects the Scots will qualify.

"Happy to do so as I am confident No 10 and other UK departments will be flying the Saltire in 2022," Mundell said on Twitter.