A KNIFEMAN dubbed "one of the most dangerous men in Britain" after attempting to murder two police officers has been told by top judges his 25-year minimum jail term was not a day too long.

John Paul Onyenaychi, 31, cut PC Paul Madden's throat and slashed at community support officer Piotr Dolata in Ealing when he was detained after revenue inspectors kicked him off a bus in December 2010.

That attack was the culmination of a five-day spree of knife crime and, at London's Old Bailey in October last year, Onyenaychi was jailed for life.

He had been convicted of two counts of attempted murder, one of robbery, one of wounding with intent to cause grievous bodily harm, plus an attempted wounding.

On Friday (15) Onyenaychi, of Stratford, east London, asked Lord Justice Hooper, Mr Justice Maddison and Judge James Goss QC, sitting at London's Criminal Appeal Court, to reduce that minimum term.

The court heard Onyenaychi cut PC Madden's throat as horrified bystanders watched and then lashed out with his knife at other officers who tried to restrain him, wounding Mr Dolata in the head.

A passing retired doctor saved PC Madden from bleeding to death and the judge passing sentence said there was "a hair's breadth" between murder and attempted murder.

Lawyers for Onyenaychi today argued the judge had not sentenced him for attempted murder, but as if he had carried out the full offence.

But Mr Justice Maddison threw the case out, saying: "We don't accept that the judge failed to allow sufficiently for this distinction.

"For the murder of a police officer with a knife for a man with his previous record, we would expect a minimum period well in excess of 30 years."