Alan Pottage says he would not hesitate to bring Scotland's rail network to a standstill and talks of using civil disobedience to support a future strike.

If that sounds hardline, there is a good reason. Mr Pottage is the Scot vying to succeed Bob Crow as Britain's most militant trade union leader.

With his shaven head and burly physique the looks are familiar - and so are the politics.

Mr Pottage, 50, is standing to become general secretary of the Rail, Maritime and Transport Union (RMT) on a pledge to follow in Mr Crow's shoes.

The union, which has 85,000 members across the UK including 10,000 in Scotland, is in the process of electing a new leader following the sudden death of Mr Crow, 52, in March.

Although four names are in the frame at present the contest is expected to come down to a straight fight between Mr Pottage, the union's chief organiser, and Mick Cash, its acting general secretary.

Both are keen to stress their ties to Mr Crow, who was a hero to union members, but Mr Pottage said that as a friend and ally for 27 years, he was the closest of all the other candidates to the former general secretary personally and politically.

Promising to build upon Mr Crow's legacy he said - like his mentor - he would not shy from confrontation to protect the pay, conditions and safety of transport workers.

Discussing his attitude to strikes, he said: "You are there to put the boot on the throat of the employer and make sure you win.

"Ninety nine per cent of our problems are negotiated, but we know the main victories we have achieved for our members, which makes us strong, have come from our members being strong enough to take industrial action.

"My job as general secretary would be to make us stronger."

He added: "Twenty four hour strikes, 48 hours strikes, there are other ways. There is no point having strikes if they are not going to achieve what members want. Our policy is to use civil disobedience, for example, that is our union's policy."

Describing Mr Crow as an inspiration, he said: "Bob was one of the softest guys I have ever known, with a heart of gold.

"But when he needed to be he was resolute, determined and could stand up to government.

"That is what you have got to do. That is what the general secretary had to do. You can't be like other trade union leaders and melt away into the shadows.

"How many trade union leaders in Britain can you name today? People remember Arthur Scargill and Mick McGahey and Bob Crow. Len McCluskey maybe. But the rest - absolutely insignificant because they are not leading. I think the workers deserve better."

He added: "I feel there is no-one better placed to continue that legacy than myself.

"It means being unpopular, but as long as you are popular with your membership and your class that is what counts."

The father-of-two is now based in Clapham, south London, but his family home remains in Portobello, near Edinburgh, and he is a Hibs season ticket holder.

Starting out as a train guard based at Edinburgh's Waverley Station, he has been a member of the RMT - which was thrown out of the Labour Party a decade ago - for more than 30 years and was brought in as full-time chief organiser by Mr Crow in 2002.

He is a veteran of numerous industrial disputes, including the 1996 guards' strike that brought ScotRail to a standstill. During the dispute he was banned from every station in the country for allegedly encouraging illegal strike action.

He wants ScotRail to be nationalised when the franchise is renewed this year, saying it is "fundamental" to the RMT.

He also promised to uphold the union's constitution, which calls for the overthrow of capitalism.

Mr Pottage supports the union's campaign for the UK to withdraw from the EU, warning membership could prevent nationalisation of the railways.

He is also a supporter of Scottish independence, although the union has not yet given its official view.

He said: "My views are the same as Bob Crow. I'm completely in favour. We have had six meetings around Scotland to see what the membership wants and the consensus is in favour of independence, but not on any narrow-minded, nationalistic basis.

"It is nothing to do with the SNP, we don't want the SNP. But we do want a chance to create an alternative, more socialist society better than the Westminster model gives us, ruled by Tories."

l The RMT is due to announce the result of its election in September.