Between them they have produced a sketch with more than two million YouTube hits, been dubbed the future of comedy by Little Britain's Matt Lucas, had a hit iPhone app, and are big in Australia.

Together BBC Scotland’s hit comedy shows Burnistoun, Limmy’s Show, and Gary: Tank Commander have gathered plaudits and fans around the world. Except, that is, in BBC headquarters in London.

Frustration is beginning to grow as the corporation has stalled in its decision whether to screen the hit shows across the BBC network. It raises the question: why is the BBC snubbing the very stars it has nurtured?

The situation has led to some of Scotland biggest names in comedy claiming that the BBC’s Oxbridge bias is working against shows with a Scottish accent.

Brian Limond, the comedian behind the surreal and dark Limmy’s Show, admitted he was “in limbo” awaiting the decision. Greg McHugh, who stars in Gary: Tank Commander, called for the BBC to live up to its pledge to screen more regional comedy on UK network TV. And the creators of Burnistoun have begun working with Channel 4 on a network sketch show, due to the “struggle” of getting their other work shown on national BBC.

Transferring hit BBC Scotland shows on to the UK network is a rarity. Rab C Nesbitt was commissioned directly from London, making its ease on to national TV screens a one-off. More recently, Still Game and Chewin’ The Fat ran for four acclaimed series each in Scotland before London came calling. Tommy Sheppard, perhaps the country’s best comedy impresario and the owner of The Stand comedy club where the stars from all three shows started out, said there is an obvious reason why the BBC in London is being sluggish in snapping up all three shows – snobbery.

He said: “I’m sure there are still people in management in the BBC who can’t get beyond the accents and who think viewers south of the Border won’t be able to understand it. I’m sure there are still such people from the Oxbridge set who are controlling our broadcasting.”

Sheppard voices a common complaint: that the BBC is dithering over screening the shows on BBC3, its digital channel designed for breakthrough acts.

“These shows are more than good enough to screen on BBC3,” he says. “It’s astounding that they won’t put them on when you consider some of the p*** that is on BBC3. And these shows won’t cost them any money. They’re already made.

‘‘We don’t all need to speak with the same accent or be in the same lower-middle-class vernacular to understand it. You can almost understand the decision not to take one of them, but to have a broad sweep and a policy of programming that ends up with taking none of them is hard to fathom.”

Brian Logan, one of the UK’s most respected comedy critics, also queried the delay. “It’s not a golden age for sitcoms at the moment, or even sketch shows,” he said.

“It’s all panel shows on the BBC at the moment. So you would have thought in that climate, why not take a punt on some of the Scottish stuff?”

The Comedy Unit, the Glasgow production company behind all three shows, said it has heard encouraging noises from the BBC’s comedy department in London.

“We’re not frustrated yet because we haven’t had a definite no,” said Rab Christie, a Comedy Unit producer. A decision on all three shows and their future on network BBC is thought to be expected in the coming weeks.

The Comedy Unit has been quietly campaigning. All three shows have had two series and the Comedy Unit has dispatched the back catalogue, together with statistics to bolster their position.

And the stats are impressive: the lift sketch from Burnistoun, for example, which features its main duo Robert Florence and Iain Connell growing increasingly frustrated with a voice-activated lift, has been watched on YouTube more than two million times.

“That’s more than anything from Gavin and Stacey, Miranda or any of the other big BBC hits,” said Christie.

Father Ted writer Graham Linehan and Little Britain star Matt Lucas have both declared Brian Limond’s sketch show the next big thing in British comedy.

Gary: Tank Commander is responsible for a top 25 iPhone app, has “huge” viewing figures on iPlayer from across the UK, has been plugged by top Radio One DJs, and the first series has just screened in Australia.

For McHugh, who created the camp soldier Gary with a weakness for Wham! on Scotland’s stand-up circuit before making the leap to TV, all this makes a compelling case for giving at least one of the shows a chance. He admits that it has been “frustrating” awaiting a decision from London, especially when the corporation has talked about screening more regional work when there is a critical mass of top comedy from Scotland just waiting to be aired.

“There has been this discussion about regional comedy for ages,” he said. “There was a very public statement from the BBC that they want to get more comedy from different parts of the country. So we’re just saying in a non-pushy way, we’ve got these three shows. You’re after regional comedy, here it is. And if you don’t, then give us feedback so we can move forward and address issues of crossover.”

The fact that all three come with thick Scottish accents should give the BBC no cause to stall, he added.

“Sometimes there is a bit of cultural apprehension to the comedy, wondering if the wider UK audience would get it. But from e-mails I’ve received and from iPlayer figures, people are watching these shows. There’s no argument over taste. There are stats to back up. People are watching, so why not give us a bash?

“So I hope there’s a market in England. I hear there’s a few Australians in England, so maybe just screen it for them.”

Limond described the wait as being “like limbo”. In the meantime, since the conclusion of his second series he has begun working on a new show. If Limmy’s Show – a series of surreal sketches featuring several recurring characters – fails to make it on to the UK-wide BBC television network he hopes his new project will.

“It’s an old-fashioned thing,” he said. “I just want to be on the telly, so I want to be UK wide. I want the most amount of people to see it. Ideally, I want it on TV around the world 24 hours a day – but that’s not going to happen.”

Limond is reluctant to suggest the delay is down to any anti-Scottish sentiment within the BBC in London.

“I could say it’s about the accent, but then find out that one of the other Scottish shows will be screened down south,” he said. “Then I’d just be sitting here thinking, no, it’s just cos they don’t like you.

“Maybe the accent to some folks in the BBC is an issue. Maybe it’s not. I don’t want to get too cocky and think the reasons why it’s not being screened down south are these shady reasons. It’s possibly something else.”

Of the three shows, the team behind Burnistoun are the most relaxed about making it to the wider BBC. Florence and Connell both wrote jokes for BBC Scotland’s last big comedy crossover, Chewin’ The Fat. They have first-hand experience about how slow the process is.

“It was a struggle as well to get Chewin’ The Fat on network,” said Florence. “And the audience for that show was bigger than all three of our shows combined. So when you’ve worked on a phenomenon and even that struggled to get its shot down south you are rather philosophical.”

He added that he never considered Burnistoun a BBC network show. Full of Central Belt patter it was always designed for Scots. Although, should it screen on BBC3 he “would have no problem if they used subtitles”.

Despite playing down their network chances with Burnistoun, they still harbour UK-sized ambitions. Last week the pair finished a script for a proposed series with Channel 4, called The Bold Florence and Connell. If approved it would screen nationally. They admit the process of potentially reaching a UK audience via Channel 4 has been much easier than with the BBC, due to its smaller size.

Yet far from turning their back on BBC Scotland they hope to work for both.

“There is a picture being painted that we’re jumping channels, which is never the intention,” said Florence.

“We’ve long-term plans for Burnistoun. We want to live and work in Scotland. And we want to do shows for BBC Scotland. We consider ourselves BBC Scotland boys, but not BBC boys in the wider sense. They are two very different things.”

It would be a shame if at least one of Scotland’s comedy hopes does not achieve network exposure, Florence added. “It wouldn’t kill them to run a repeat of one of the series.”

In the meantime both himself and Connell will continue to write and wait for the rest of the UK to tune in.

“We’ll try and make a show for people down south but still continue to make Burnistoun for people in Scotland,” he said. “And whatever will happen will happen.”