(Adds royal mail comment)
By Stefano Ambrogi
LONDON, Oct 13 (Reuters) - Union leaders representing workers at Britain's state-owned Royal Mail offered management a last-ditch deal to avert a national strike that would cripple deliveries across the country, they said on Tuesday. The Communication Workers Union (CWU) said it had written to Royal Mail Managing Director Mark Higson asking him to meet a number of key conditions or it would press ahead with strikes.
In the letter, union bosses presented Higson with demands that included revealing his business plan for the whole of the planned transformation process, rewarding workers for the firm's future success, a commitment to openly discuss staffing levels and pay and an agreement to initiate an inquiry into bullying and harassment of workers.
Royal Mail said the strike threat was "a blatant and deplorable attack on customers and on the future of the UK postal service".
"Today the CWU has written to us with a `peace offer' which is in reality a series of fresh demands against Royal Mail," Higson said in a statement.
Workers voted overwhelmingly last week for a nationwide strike, escalating a dispute which has already caused widespread disruption to postal services.
A national strike could cost the British economy 1.5 billion pounds ($2.4 billion) and deal a blow to online retailers, according to analysis commissioned by shopping comparison website Kelkoo.
A CWU spokeswoman said if the latest negotiation failed, national strike dates will be announced on Thursday Oct. 15.
The government said the planned nationwide strike "defies logic" and would not resolve differences.
"It would be a suicidal act -- turning more hard pressed consumers and businesses away from using mail," said Business Secretary Peter Mandelson.
David Frost, director general of the British Chambers of Commerce, said the threat of a strike was a serious knock to business confidence.
"The run-up to Christmas is a vital trading period for firms and if this strike goes ahead orders will be lost and the fragile recovery will be undermined," he said. (Additional reporting by Michael Holden; Editing by David Cowell)