Firms have been urged to tackle the prospect of allowing staff to work flexibly during the football World Cup so they can watch games without disrupting business.

The conciliation service Acas issued new guidance in a bid to avoid workplace clashes when the tournament starts in Brazil on June 12.

Employers were advised to have agreements in place to deal with requests for time off, sickness absence or watching TV or websites.

Acas chairman Sir Brendan Barber said: "The World Cup is an exciting event for many football fans but staff should avoid getting a red card for unreasonable demands or behaviour in the workplace during this period.

"Many businesses need to maintain a certain staffing level in order to survive. Employers should have a set of simple workplace agreements in place before kick off to help ensure their businesses remain productive whilst keeping staff happy too.

"Our guidance published today can help managers get the best from their team players and avoid unnecessary penalties."

Employment law company Shakespeares suggested that firms could trial extended flexible working rights which are due to take effect from the end of June.

Phil Pepper, a partner at Shakespeares, said: "From the end of June, all employees will have the right to request flexible working rights - not just those that have children under the age of 17 or responsibilities as a carer.

"By extending these rights to the workforce early, as part of a World Cup trial, employers could do a lot to boost workplace morale and reduce absenteeism.

"While precautions should be taken, there is scope for employers to be creative about incentives that might help to discourage absenteeism and keep football fans happy and motivated during working hours.

"A dedicated viewing area could be created to allow employees to watch matches or check scores during their breaks, for example. Incentives in the form of rewards for a 100% attendance record during the months of June and July could also be considered."

John Allan, chairman of the Federation of Small Businesses, said: "Our members, many of whom are small family firms, will find this guidance useful during the World Cup period as it will help them to comply with the law while avoiding confusion among managers and employees during a period when national excitement will be at fever pitch.

"Provided that employers agree and communicate a clear set of workplace rules with their staff before the World Cup kicks off, this should avoid problems and help them maintain necessary staffing and attendance levels."