TORY MP Alan Duncan told a court yesterday that it took four 999 calls to get police to the scene of an attack on Conservative Party chairman Dr Brian Mawhinney.

He said that, despite requesting their ``swift attendance'', it was at least 20 minutes before officers turned up.

In the end he attempted to make a citizen's arrest of some of those allegedly involved in the paint and flour protest against the Immigration and Asylum Bill.

London's Bow Street Magistrates Court heard the delay was later the subject of a top-level police inquiry which resulted in police apologies to both the Cabinet Minister and his parliamentary private secretary, Mr Duncan.

Before the court were students Karen Doyle, 19, of Leverton Street, Camden; Naveed Malik, 18, of Kenninghall Road, Clapton; Amanda Egbe, 20, of Linthorpe Road, Stoke Newington; Nick De Marco, 28, of Beamont Court, Upper Clapton Road, Clapton; and teacher Anthony Gard, 54, of Finland Road, Brockley, all London.

They all deny two charges of common assault and one of threatening behaviour on November 15 last year.

Stuart Sampson, prosecuting, claimed that all except De Marco were directly involved in hurling plastic bags of orange paint and flour at Dr Mawhinney and his wife, Betty.

One of the bags of paint caught the politician on the back, splattering Mrs Mawhinney in the process.

Mr Sampson said the Crown's case against De Marco, a former history and philosophy A-level student and president of the students' union at King's College, Camden, north London, until his expulsion after the attack, was that he ``actively encouraged'' the others to take part in what occurred.

Peterborough MP Dr Mawhinney, who had to run a gauntlet of placard-waving demonstrators, chanting ``racist, racist'' as he arrived and left the heavily-policed court building, spent 40-minutes in the witness box.

Dr Mawhinney recalled how they had just left the House of Commons and were walking across nearby Abbingdon Green to take part in interviews in a temporary BBC studio, when a barrage of paint and flour ``missiles'' were hurled at him.

Realising the attack was aimed at him, he tried to ``put some distance'' between him and his wife in a bid to draw their fire.

MP Mr Duncan said he and Sheila Gunn, head of public relations at Conservative Central Office, happened to be walking towards the Mawhinneys when the attack occurred.

He said he ``clearly'' saw three girls take part in the first stage of the attack which involved three or four bags of flour being thrown, followed by paint and then more flour.

A fourth person, ``more reticent than the others'', threw something at the very end.

Mr Duncan told the court that, once the Mawhinneys were safely inside the studio, he borrowed a cameraman's mobile phone to dial 999 for the police.

``I said there had been an attack on a Cabinet Minister . . . and their swift attendance was called for.

``But in the course of 20 or more minutes that ensued, I made a total of four phone calls,'' he said.

During one of them the police operator advised him he was entitled to make a citizen's arrest if those involved tried to get away.

Mr Duncan said after his third call they attempted just that.

Television news footage played to the court showed him running after them and eventually putting his arm around one of the women defendants.

``I said to them that I am entitled to make a citizen's arrest, but please wait until the police arrive.''

The trial continues.