Great Britain to have united team at 2012 Olympics, says Blatter

Blatter said that Fifa had given written guarantees that fielding a host British team will not interfere with England, Scotland, Wales and Northern Ireland maintaining their separate identities. He said: "We have confirmed in writing that they have to provide a Great Britain team for the 2012 Olympics, but the four British associations will not lose the rights and privileges acquired back in 1947.

"They will play with one team but it is up to them how they do it. It can be a mixed team, it can be from just one of the home nations, whatever they want to do."

Britain qualify automatically as Olympic hosts, but it is unlikely there will be a British Olympic football team after 2012 because no united British team plays in the European Under-21 Championship, which acts as the qualifiers.

The Great Britain team is limited to players aged Under-23 but three over-age players are allowed. The development raises the prospect of the likes of Wayne Rooney teaming up with the cream of Wales, Northern Ireland and Scotland in London in 2012, with a possible final at Wembley.

Argentina are the reigning Olympic champions after beating Paraguay 1-0 in Athens last year.

The FA executive director David Davies welcomed Blatter's remarks. Davies, the FA's representative on the British Olympic Association and the head of a working group looking at ways of fielding a British team in 2012, said: "What Blatter has said is welcomed by those of us who believe we have a positive contribution to make to football and the Olympics. We would hope people will be open-minded about this and certainly Fifa have made that position clear. We have had a working party looking at the options and we will come forward with those and see what is the best way to achieve unanimity."

Scotland's reluctance to get involved may now change because Glasgow is bidding to host the 2014 Commonwealth Games and will need the support of the BOA. But an SFA spokesman last night said: "Fifa have said before that this is a matter for the British associations to decide. We are not currently party to any discussions on this and we have made our views entirely clear about an Olympic team. So the position has not changed as far as we are concerned."

Blatter also announced last night that Fifa will use goal-line technology at next year's World Cup in Germany if a trial run at the Under-17 World Championship in Peru, which run, from 16 September to 2 October, proves a success.

A "smartball" system has been developed whereby balls fitted with a microchip will send a signal to the referee when they have crossed the line. "We will definitely use the technology in Germany if the experiment works," said Blatter. Fifa will make a final decision next month.