A SERIAL offender who held a knife to the throat of an elderly taxi driver and threatened to kill him, has been re-sentenced to an indefinite spell behind bars.

Nicholas Rankin, 32, had been jailed for eight years last month for attempting to rob 74-year-old Gordon Smith in Totton after a judge was wrongly told it did not constitute a specified offence.

The blunder was later spotted and Rankin has since returned to court where he was told he would now serve a minimum of four years as a dangerous offender before his case could be considered by the Parole Board.

Judge John Boggis QC reminded Rankin, pictured left, that he had told him at the earlier hearing, he would have received an indefinite sentence for public protection if the attempted robbery had then been recognised as a specified offence.

Prosecutor Richard Willcox told Southampton Crown Court the offender had previous convictions for robbery in 1992 and 1994, assault with intent to rob in 1996 and aggravated burglary in 2002.

He targeted Mr Smith - who suffers from a heart condition and has been fitted with a pacemaker - within days of being released from prison.

The cabbie feared for his life after Rankin chillingly told him that he was on the run, he had murdered one person and threatened to make him his next victim.

But Mr Smith thwarted Rankin by "rolling" out of the driver's seat and running up the road to a supermarket to raise the alarm. Rankin was arrested minutes later in a nearby pub.

Rankin, of Northbourne Close, Dibden Purlieu, had pleaded guilty. Defence lawyer Charles Gabb said that fact was the sole point of his mitigation.