Keith Brown: £10 billion spend on high-speed rail link to Scotland an "absolute must"

He told he audience in Glasgow that HS3, the planned extension of the £50bn HS2 rail line into northern England, must be stretched further.

He said: "There's a massive disadvantage if HS3 doesn't come to Scotland.

"My main point is that if it's going to happen, and it looks like it's going to happen, it's essential that it comes to Scotland. If you start to get sub-three hour journey times [to London], then you start to see people making that modal shift from air back to rail.

So if it's going to happen, then it absolutely must come to Scotland."

Asked how much that might cost, he said the Scottish Government would pay its share which he estimated would be "somewhere in the region of £8-10bn".

He added: "There's no reason why we have to build from the south up. We can start at the top and work south at the same time."

The event, organised by the solicitors' firm, Brodies, in conjunction with The Herald, also included representatives of Labour, the Conservatives and LibDems.

Mary Fee, Scottish Labour's Shadow Cabinet Minister for Infrastructure, agreed that it was "economically essential" that HS3 come to Scotland, while Dr David Montgomery - who is the Conservative candidate vying for Jim Murphy's East Renfrewshire seat - said HS2 and its extension lines "should work for the whole country".

Only the LibDems opposed the move.

Gary McLelland, who is challenging for the Glasgow East constituency in May's election, said: "We don't see the case to extend it to Scotland at the moment. When you look at somewhere like Aberdeen with its oil industry that is so vital to Scotland's economy then I think an electrified line from Edinburgh to Aberdeen is a much more pressing need that spending £8-10bn on HS3."

Phase one of HS2, due for completion in 2026, will connect London to the West Midlands, with phase two extensions to Manchester, Sheffield and Leeds expected to be completed by 2033.

CBI Scotland and Network Rail have also backed future lines linking Glasgow, Edinburgh and Newcastle into the high-speed network, arguing that it could cut journey times between Edinburgh or Glasgow and London to three hours.

Mr Brown also told the audience that he "regularly sees appalling behaviour from cyclists" on the roads and called for more cooperation between motorists and bike users.

Mr Brown, who was transport minister until last year, said: "Dedicated infrastructure [for cyclists] is something that splits opinion. Some are keen, others less son. But what a lot of people don't realise is that we as the Scottish Government only have control over four per cent of the roads in Scotland.

"London has done a lot of interesting work in terms of [cyclist awareness training for] HGV drivers, and Lothian Buses in Edinburgh is another good example.

"But the responsibility has to go both ways. I regularly see appalling behaviour from cyclists and I see it from motorists too. So we need to respect one another's space."

One audience member said Lothian Bus drivers were now so courteous to cyclists following awareness training that it was "almost laughable", but called for the same training to be made available to taxi drivers and private motorists who were "the most dangerous" to cyclists.

Ms Fee said: "It's not about one thing. It's about more cycle lanes, slower speeds, driver training, and cyclist training."

She added that she would like to see more cycle clubs in schools to train children how to cycle on roads and build up their confidence.

The panel was almost unanimous in its support for a third runway at Heathrow over Gatwick's bid for a second runway, with only Mr Brown sitting on the fence.

He said the Scottish Government would support "whichever airport guarantees the slots we need and the regional pricing that we want."