Thorman captained England in 2005

The Giants half-back has caught the eye in recent weeks to help his side reach the Challenge Cup final and away from relegation trouble in Super League XI.

The 25-year-old has also signed a new contract that will keep him at the Galpharm Stadium until the end of 2009.

"I am delighted," said Huddersfield coach Jon Sharp. "He is an excellent leader both on and off the field."

Thorman added: "It is good to have your efforts recognised and it is particularly good to have the contract issue sorted out."

Thorman is in his second spell with Huddersfield and has after stints with London Broncos and NRL side Parramatta Eels.

He has yet to play for the Lions but has represented and captained England.

"He has always been part of our deliberations," said Lions coach Brian Noble.

Sharp, who is also Noble's assistant, added: "I am very pleased for Chris. He has been at the top of his game recently and he has received his just rewards."

The GB squad, which now consists of 43 players, will be trimmed to 25, with 10 on standby, on 25 September.

The Lions have arranged a warm-up game against a Newcastle select side on 20 October, to be played in Newcastle, but the team will not feature those players involved in the Super League Grand Final.

Sharp and Dave Lyon will be in charge for the match against Newcastle, with Noble flying out with the rest of the squad after the Grand Final at Old Trafford on 14 October.

Britain begin their Tri-Nations campaign against New Zealand in Christchurch on 28 October.