ENGLAND supporters have been urged to be on their best behaviour tonight as the new international season opens in Ipswich.Football Association spokesman Paul Barber said fans attending England's friendly fixture with Croatia at Portman Road should continue their recent "exemplary" showings.

ENGLAND supporters have been urged to be on their best behaviour tonight as the new international season opens in Ipswich.

Football Association spokesman Paul Barber said fans attending England's friendly fixture with Croatia at Portman Road should continue their recent "exemplary" showings.

The national side could be in danger of being thrown out of the 2004 European Championships if fans fail to behave and there is any repeat of the violence that marred the win over Turkey in April.

Police have warned known troublemakers at clubs in the South East to stay away from the match for fears of clashes between rival supporters.

That includes "high risk" Norwich City fans, in a bid to prevent any trouble with Ipswich Town followers. There will be 600 police officers on duty for the match, the biggest force operation in Suffolk's history.

Mr Barber, the FA's director of marketing and communications, made his plea for a peaceful night after a "new generation" of hooligans contributed to a 19% rise in the number of football-related arrests last season.

"The behaviour of the England fans has been absolutely exemplary over the last three games and we must do everything that we can to ensure that continues tonight and in our big European qualifiers coming up next month," he said.

"We take the Home Office figures very seriously and are encouraged that the increased number of arrests reflects a tougher policy towards violent and anti-social behaviour at football matches.

"The majority of the arrests at England games took place in one match – against Turkey at Sunderland – and even then it was the mindless minority that caused the problems.

"Since that game and the subsequent action taken by UEFA, we have done our very utmost to ensure that everyone is aware of the implications that further racist or violent behaviour could have on English football."

Suffolk police have warned there will be a "zero tolerance" policy against anti-social, criminal or racist behaviour at the match.

The officer in charge of policing the game, Supt Carl Puiy, said: "The plans are going very well. The process started in May and it has been very complicated.

"It's categorised as a high-risk match – the same as Ipswich versus Norwich, but maybe a little higher.

"My concern is not so much about England hooliganism. It is more about what will happen as a result of local rivalry.

"I've written to known, high-risk supporters in Norwich informing them in the strongest possible terms not to come to Ipswich tonight.

"We have also got some spotters coming down to the match from Norfolk police for the evening.

"Their job is to identify known troublemakers from the city and inform us who they are and what they are doing.

"There will also be spotters from the England spotting team to identify those who have been known to cause trouble at internationals."

He added: "Obviously, England are in danger of being expelled from Euro 2004 if there's any more problems, and we do not want that to be because of something that happens in Ipswich."

Officers have been drafted in from Norfolk, Cambridgeshire, British Transport Police and the Metropolitan Police to boost numbers.

Police have asked people without a ticket for the big game to steer clear of the town centre tonight.

Publicans have also been told to serve drinks in plastic bottles and glasses and to remove any outside tables or chairs that could be thrown.