Union leaders today claimed threats and intimidation have been used against striking bus drivers after workers set up picket lines for the second time in five days.

Between 20 and 30 Stagecoach drivers waved placards at passing motorists outside the Marine Parade depot.

A similar picket line on Saturday forced Stagecoach to draft in managers, inspectors and directors from across the country to drive buses.

Transport and General Workers' Union regional industrial organiser Paul Bouch said Stagecoach had threatened not to give back pay and had locked workers out of the depot after Saturday's strike.

The drivers want £7.50 an hour but Stagecoach have imposed a £7 limit.

Mr Bouch said: "We are hoping the strike and the solidarity of the workers will show the company they are not going to give in.

"Threats and intimidation will not work. Moral is extremely high and the workers are laughing and joking while being extremely committed to the cause."

Union branch secretary Paul Cowell said part of Stagecoach's pay offer was an attendance bonus.

He said the bonus would force drivers to go to work, even when ill, to avoid losing the extra £10 a month they would get for full attendance.

Mr Cowell said: "If a driver went on holiday they do not get the bonus. If they are sick, they do not get it. If they take a day off, they do not get it.

"You can be sick for a day and lose a month's bonus.

"What the company is doing is making drivers come to work when they are sick so the company can achieve the 8.3 per cent pay deal. This is unfair and would penalise drivers who are sick."

Stagecoach has 150 buses and 300 staff in its West Sussex and South Hampshire division.

Stagecoach managing director Andrew Dyer said about 60 drivers of the 70-driver shift were either picketing or did not turn up for work. More managers had been drafted in.

Mr Dyer said: "There has been no agreement on back-pay. We have not said 'that's it, you're not getting back pay if you strike'."

He said not letting employees go back to work if they turn up halfway through a shift, was "just normal practice, not threats and intimidation".

On the attendance bonus, Mr Dyer said: "Saying it would force sick drivers to go to work is a very negative way of looking at it.

"We have a situation where inflation is around three per cent and we have offered the drivers a five per cent increase in wages.

"Over and above that, we have said we'll give an extra £10 as an attendance bonus, which is quite unashamedly to encourage good work attendance."