David Cameron has said he will fly the flag of St George over No 10 during the football World Cup in South Africa.
The prime minister told MPs that the move would not cost anything and he hoped it would help unite the nation behind the England team.
He said he hoped that no matter what part of the UK MPs represented, they would be shouting "come on England".
Mr Cameron wished the team and manager well ahead of their first match, which is against the US on Saturday.
Meanwhile, Local Government Minister Grant Shapps has written to all council chiefs in England telling them to take a "common-sense approach" over any potential health and safety fears caused by people flying the flag of St George during the tournament.
As the residence of the prime minister of the United Kingdom, the union jack is normally flown above No 10.
But at his second weekly session of prime minister's questions, Mr Cameron was asked by Conservative MP Nadhim Zahawi whether he would hoist the English flag instead during the tournament, for which none of the other home nations qualified.
"There was some question that this was going to have a cost impact but I have managed to cut through that and I can say, at no additional cost to the taxpayer, the flag of St George will fly above Downing Street during the World Cup," the prime minister replied.
"For the purposes of this, I am looking at all the benches here and I am sure that everyone in this House, no matter what part of the United Kingdom they come from, will be cheering 'Come on England'."
Mr Cameron did not say whether the flag would remain aloft for the entire competition or whether it would come down should England be eliminated before the final on Sunday 11 July.
The prime minister's official spokesman later confirmed that the England flag would fly over Downing Street from this Saturday morning, ahead of the Trooping of Colour ceremony, and would also fly over the Department of Culture, Media and Sport.
He said it would be up to individual secretaries of state to decide whether they also wanted to do this at their departments but if they did, they would need a separate flag pole as they had to continue flying the union jack too.
In his letter to local authority leaders and chief executives, Mr Shapps said the World Cup was a "great opportunity to foster community cohesion".
He said he understood a risk-based approach to health and safety was important, but urged local authorities to work "to avoid accusations of being over-zealous or spoilsports".
He added: "Some extremist groups have in the past tried to lay claim to the Cross of St George.
"The World Cup is an important opportunity for councils to do their bit in helping reclaim the English flag as a proud symbol of our nation's identity and encourage local communities of all backgrounds to pull together in support of our national team."