Prime Minister Tony Blair is only a ''fair-weather supporter'' of Newcastle United, his Cabinet colleague Jack Straw said today.

Mr Straw, a keen fan of Blackburn Rovers, said he was hoping his team would be drawn against Newcastle in the semi-finals of the FA Cup later today, rather than the other two remaining contenders, Arsenal and Manchester United.

But he said that a Blackburn-Newcastle tie would not put him at loggerheads with the Prime Minister.

''He is a fair-weather supporter,'' Mr Straw told the BBC Radio 4 Today programme. ''I don't think he gets to many games.''

Mr Straw and his children have had season tickets at Ewood Park for 15 years and attend most home matches. He joked that his support for Rovers was ''a life sentence''.

He revealed his sons had updated him on the team's progress in their fifth-round Cup replay with local rivals Burnley by text message during an official dinner with US Secretary of State Condoleezza Rice.

''I wasn't jumping up and down, I was paying attention to what was a very serious discussion,'' he recalled.

''But I think she was slightly bemused that I had to consult what appeared to be my knee.''

Mr Straw, who is Blackburn's MP, said his ''dream draw'' would be Newcastle in the semi-finals - Rovers' first appearance at this stage of the competition for 45 years - then ''to meet and beat Manchester United in the final''.

Asked if he truly believed his soccer heroes were on their way to glory in the FA Cup final at Cardiff's Millennium Stadium, he replied: ''I never make predictions, I just pray.''