The former baggage handler was "stable" in intensive care after suffering an asthma attack.

A source said that the family were called to the hospital at 5am yesterday after his condition deteriorated, but that it later stabilised.

Prime Minister Gordon Brown called the Smeaton family yesterday to offer his support.

Mr Smeaton, 32, shot to fame after attempting to foil the Glasgow Airport attack last June and was taken ill as the two men accused of the incident went on trial.

His fiancée Christy MacPhedran, 32, flew in from New York on Saturday to be with him and headed straight to his bedside at Paisley's Royal Alexandra Hospital.

She told the Sunday Mail: "I got the first flight I could. I'm worried sick about my John."

The couple are planning to set up home together in America.

Mr Smeaton was reportedly watching television with his parents when he collapsed.

His father Iain told the paper: "John was struggling to get a breath. It was terrifying to watch.

"He's never had an attack this serious before."

Mr Smeaton was admitted to the hospital on Thursday.

The former baggage handler has regularly written about his poor health in a national newspaper column.

Sources said a similar asthma attack a decade ago almost killed him.

Bilal Abdulla, 29, and Mohammed Asha, 28, went on trial at Woolwich Crown Court, south-east London, on Thursday accused of attempting to murder hundreds of people with car bombs in London and Glasgow.

Mr Smeaton is in the hospital where Abdulla was working as a junior house officer in general surgery at the time of the airport attack.

The former airport worker, who recently revealed he was quitting Scotland for a new life in America, became an overnight celebrity after the incident.

His efforts to foil the attack, followed by comments in a TV interview broadcast shortly afterwards across the globe, catapulted him to fame.