The image could not be more wholesome. Angus MacNeil, more than 400 miles from the Westminster corridors of power, has always been happy being pictured digging potatoes or tending sheep at his family croft.

The image could not be more wholesome. Angus MacNeil, more than 400 miles from the Westminster corridors of power, has always been happy being pictured digging potatoes or tending sheep at his family croft.

The married MP believes he is the first working crofter to sit in the House of Commons. He is also one of the most effective Nationalists ever to take a seat in the chamber.

It was Mr MacNeil, fresh on the green benches, who remembered what more experienced politicians had not: that selling honours was against the law.

Just months into the job, he complained to the Metropolitan Police that four of the millionaires bankrolling the Labour Party with secret loans had been nominated for peerages.

The complaint last March was to lead to detectives interviewing a serving Prime Minister at No 10 for the first time. It also propelled Mr MacNeil on to the Westminster A-List.

Cash-for-honours has overshadowed the final months of Tony Blair's premiership. Many had dismissed the complaint as a political stunt or, in the words of Mr Blair's spokesman Alastair Campbell, "political opportunism". But not the police. Their investigations have taken them into the heart of Westminster's political machine and continue to this day.

Last year, the 36-year-old was named Best Scot in Westminster in The Herald Politician of the Year awards.

Mr MacNeil won his seat in the elections of May 2005, just two months before the "mistake" he made with two teenagers in Shetland. Weeks later, his wife Jane gave birth to their daughter. An ardent Nationalist, he fought and lost a mainland seat in the general election of 2001.

Mr MacNeil had had a varied career for a man so young. Still crofting, his last job before Westminster was as a primary teacher at Eoligarry school in the north end of Barra.

However, he had also worked in broadcasting - for the BBC in Inverness - and has a degree in civil engineering from Strathclyde University. Mr MacNeil is a native speaker of Gaelic and led a sheltered early life on Barra. His parents bought their first television when he was 10.