The BBC is facing up to two days of strike action on May 19-20 in protest at director general Mark Thompson's plan to cut 4,000 jobs.
Union representatives say there has been a groundswell of support for industrial action among staff at the corporation ahead of next week's ballot.
A tour of BBC national and regional centres by representatives from the National Union of Journalists and the broadcasting union Bectu has found the majority of members appear to be keen to disrupt programmes.
Around 250 people attended a meeting in Cardiff yesterday and representatives from the regions say support is building for a "yes" vote.
"What's coming out strongly is people want BBC-wide disruption, between 24 and 48 hours long. The BBC can cope with 24 hours but longer than that will be a problem," said one representative.
Ballot papers were sent out earlier this month and have to be returned by noon on May 11.
The result will be announced a couple of hours later. If a majority vote in favour of industrial action then the unions involved - the NUJ, Bectu and Amicus - will meet on May 12 to decide what form it should take.
They have to give seven days' notice to the corporation, which means the earliest opportunity for disruption is on May 19.
However, it seems that the FA Cup final on May 21 may escape unscathed.
The NUJ general secretary, Jeremy Dear, said: "If our members vote yes then it's likely we'll have a ballot at the earliest opportunity. But whether Saturday is a good day to be having the action is another matter.
"After the initial action, subsequently we will look for particular events which we think will have the biggest impact. Some of the outside broadcasts may well be looked at as a possibility."
BBC News 24 journalists have already made their voice heard and have employed a strict work-to-rule policy in protest at Mr Thompson's proposed cuts.
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