BBC Scotland has been thrown into turmoil over plans for a "Scottish Six" early evening news programme.

Furious journalists yesterday threatened to block the project unless BBC Scotland boss Ken MacQuarrie agreed to a full consultation on proposals to create a new hour-long bulletin.

Staff are furious about an "insulting" internal document - seen by The Herald - which casts doubt on the ability of the present Glasgow-based news team to produce and lead the programme.

They are also angry at learning of the plan in the Press and being kept in the dark over a series of crucial pilot shows, which bosses want to see within weeks.

Around 60 journalists voiced their concerns during an emergency union meeting at the corporation's Pacific Quay HQ in Glasgow.

A source said: "We need proper consultation by the end of the week.

"If that doesn't happen I can't see how we would avoid a formal dispute.

"That would mean nothing could happen until the situation was resolved."

A 17-page memo, which gives running orders for a possible new-look bulletins, says the current BBC Scotland team "has some strong talent but not enough depth of specialism".

It also states the "ideal" new editor of the Scottish Six would have high level experience of network TV, implying many senior Scottish journalists would not be considered good enough to spearhead the programme.

The leaked memo, headed 'Proposals for TV News Hour,' outlined three possible new programme formats.

Contrary to some reports, they would retain big name 'network,' or UK-wide, presenters and correspondents on Scottish screens.

The first option would be presented entirely from Glasgow.

The second - understood to be the preferred format - would be fronted by a main presenter in Glasgow and a second anchor in London.

Both would cost an extra £4.5m to £5m per year to produce, with around 70 extra staff required.

A third option would retain the present split between the UK-wide Six O'Clock News and Reporting Scotland.

It would cost an extra £3.5m.

Staff are unclear whether pilots for all three formats are to be made.

The sample programmes would require the co-operation of big name London presenters and correspondents around the world.

BBC Director General Tony Hall has asked to see the pilots within three weeks, Glasgow staff have been told, sparking fears they could undermine the quality of current programming.

The source added: "People in the news room feel insulted.

"It is not clear how people will produce these pilots.

"Of the three templates, we believe the preferred one is the crazy plan to split coverage between Glasgow and London, which we would be totally opposed to."

Another source said: "We are already stretched.

"You'd expect pilots like this to take two months to produce, not three weeks."

An National Union of Journalists source said: "People have gone ballistic.

"They are raging. There is a massive backlash against it.

"There is a lack of transparency, that's what's worrying people. There is no strategy or plan in place."

BBC Scotland staff learned of possible plans for the "Scottish Six," in a press report on Tuesday.

Later that day, Gary Smith, BBC Scotland's head of news and current affairs, emailed colleagues to confirm new formats would be piloted.

He stressed no final decision had been taken.

The leaked document also confirmed the lack of clear public support for a Scottish Six.

It said focus groups in Glasgow, Edinburgh, Kirkcaldy and Nairn, which were shown the proposals, declared "a strong interest in a UK perspective on UK and international stories".

It added: "Support for a Scottish Six was muted and, at the very least, it is recognised that BBC Scotland would have to address perceived quality issues first".

It said the two new-look bulletins "would clearly be a risk to audience numbers".

One senior insider defended the move, saying: "This is a package that would create 60 top quality jobs in journalism but the NUJ is whingeing.

"They should be singing from the rooftops."

A BBC spokesman said: "We’ve said very publicly that we’re conducting a news review at present and we’ll be looking at various different programme formats and carrying out audience research as part of that process.

"We have told our news teams that we will be carrying out some non-broadcast pilots and we’ll obviously talk to staff as we proceed with this work and discuss fully any implications on them.

"No decisions on our future output will be taken until that work is concluded but ultimately our aim is to deliver the very best news offer for our audiences here in Scotland."