Prof Michael Keating expressed caution of the exit poll in Scotland.

He said across the UK the exit poll had been shown in the past to be very reliable with more than 30,000 people surveyed at 144 polling places.

However he added: "We don't know how many were in Scotland. You need more than 10% in Scotland to get a reliable sample in Scotland.

"It may just be that the Scottish figures are less robust than the UK figures."

He says he thinks Scotland may have been less than 14 polling stations sampled.

He said: "So the confidence in translating votes into seats in Scotland might not be as strong as it would be across the UK."

The SNP MSP for Carrick, Cumnock and the Doon Valley, Jeane Freeman, said: "From the SNP point of view, if we have the majority of seats in Scotland, then that would be a good result for the SNP.

"In 2016, we had six MPs. 2015 was an extraordinary, probably once-in-a-century result, so 34 - we would hope for better.

"I'm sure we will get better but it's not a disaster for the SNP. It is a disaster for the Tories tonight."

Brian Taylor
BBC Scotland Political Editor

Another thought re the exit poll. It is, as I said on air, only a sample, albeit a pretty big one. Final campaign polls mostly suggested a big lead for Tories although one or two indicated much smaller.

• Follow my blog as the results come in

Conservative MSP Murdo Fraser tells BBC Scotland: "In Scotland [the exit poll] shows the SNP on 34 seats. That would an astonishing decline for the SNP who go into this election holding 56 seats out of 59.

"To end up with 34 seats in Scotland would be a dramatic reverse for Nicola Sturgeon."

The Exit poll has put the SNP on 34 seats, down 22.

The SNP's Aileen Campbell told BBC Radio Scotland: "That would still put us with the most seats across the country.

"If we had had that result in 2015 we would have been cock-a-hoop.

"I think we would be disappointed to lose a number of hard-working MPs but we'll see how the night pans out."

Brian Taylor
BBC Scotland Political Editor

Exit poll suggests 314 for Tories, short of majority. If it is correct, then Theresa May has lost any pretension to a renewed mandate for negotiating Brexit - and would face big questions from within her party.

In Scotland, poll suggests 34 for the SNP, down 22. Jeane Freeman of the SNP places emphasis on poor result for Tories.

The exit poll suggests that the SNP will get 34 seats - down from 56 in the last general election.

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In exit poll just published by the BBC, ITV and Sky indicates that the Conservatives will be the largest party but will lose 17 seats with a projection of 314 seats.

The poll suggests Labour will get 266 seats -- a rise of 34 seats. It puts the Liberal Democrats at 14 -- an increase of six, SNP 34, Plaid 3 and Greens 1 and UKIP will lose their only seat.

The other parties will account for 18 seats

You'll be able to find out the winners and losers in your local area on BBC Scotland's constituency pages.

And you can find out what time your constituency is expected to declare its result here.

BBC Scotland will be delivering comprehensive election results coverage across online, TV and radio.

There will be analysis, background, reaction and debate as we find out the results of Scotland's 59 Westminster constituencies.

The counts of all 650 UK seats will be covered, along with who becomes the next prime minister.

TV and radio highlights include:

• An overnight television programme, starting at 21:55 on BBC One Scotland will be presented by Glenn Campbell, Brian Taylor and Jackie Bird. It will run until 09:00 on Friday.
• David Henderson will be performing his "magic" with a virtual reality presentation of the results as they happen.
• Punditry aplenty will come from Fiona Stalker's guests at BBC Scotland's election cafe. You can follow #BBCElectionCafe on social media for the latest talking points.
• On BBC Radio Scotland, live coverage of the results will start at 22:00 and be brought to you by presenters Bill Whiteford and Gillian Marles.