A war of words flared over the bitter postal workers' dispute today when the head of the Royal Mail accused a trade union of talking "cobblers".
Chief executive Adam Crozier disputed claims by the Communication Workers Union about working practices in the postal organisation.
The union's deputy general secretary, Dave Ward, has accused the company of "slavery" over the way it makes its staff work.
But Mr Crozier described the claims as "cobblers" and said the Royal Mail was only trying to make people work the hours for which they were paid.
He told the BBC Radio 4 Today programme that the two sides were close to reaching an agreement on pay and pensions, leaving flexibility as the outstanding issue.
Up to 130,000 union members remained on strike today, crippling mail deliveries across the country.
Last night, the union announced a series of fresh strikes starting next Monday unless the deadlocked dispute is resolved.
Mr Crozier said: "I doubt there is a company out there that does not ask its people to work all the hours they are paid for.
"For the union not to accept that is not a tenable position."
Mr Crozier claimed there were 1,442 so-called "Spanish practices" in the Royal Mail a few years ago which had been cut to 92.
"You cannot have that situation in the modern world. These are practices that went out in the 1970s in practically every other company."
He claimed one example was that postal staff asked for overtime if they finished two hours early and were requested to do other duties to complete their shift.
"All we are asking is that people work the 37 hours 20 minutes for which they are paid. If they work longer than that, of course they will receive overtime."
Mr Crozier said Royal Mail staff were paid 25% more than workers in rival post firms.
He said other companies in the business were 40% more efficient, which is why the Royal Mail wanted a long-term solution to the current dispute to help it compete more effectively.
Talks aimed at resolving the row ended without agreement last night.
The current strike will continue until 3am tomorrow.
The union has announced a series of rolling strikes involving different parts of the service from next Monday.
Mr Crozier claimed people were beginning to return to work despite the strike, although this was disputed by the union, which said the industrial action was being "solidly supported".Reuse content