Dr Jekyll...

enjoys a close working relationship with all his staff

A survey has found that British workers spend an average of 45 hours socialising with colleagues or clients in the run-up to Christmas.

Come January, many will need that time again to apologise for their conduct and try to escape disciplinary action.

Mr Hyde...

seeks to reinforce that by brandishing a bunch of mistletoe, and offering female colleagues a "Christmas kiss"

Office parties are as wild as they ever were, says professional party organiser, Denis McCourt.

"There's always someone who arrives at 6pm, hits the booze hard, and two hours later they're dancing on the tables.

"But office parties are very self-regulating. If a staff member is making a fool of themselves, someone more senior will usually say 'Look, behave yourself, the boss is just over there'."

Yet the fall-out can be more serious than a thumping hangover and becoming the stuff of office gossip legend.

The Industrial Society takes numerous calls each year from employers seeking to untangle post-party predicaments.

Spare workmates the smooth moves and midriff

"Often they are to do with an employee who has drunk too much and got into a fight or some sort of harassment, driving home drunk or causing damage to the venue," said a spokesman.

At the start of every year, law firm Eversheds is busy sorting out cases in which employers try to discipline staff for party excesses.

They usually hinge on whether the employee knew they were behaving in a way that was unacceptable to the company, says employment partner Owen Warnock.

Boss as bouncer

Eversheds advises its clients to instruct managers to step in should matters get out of hand.

"And if past history indicates things go rather over-the-top, we advise them to set ground rules before the event," he says.

Dr Jekyll...

is frank and honest when it comes to workplace politics

This is because the company can be liable if a complaint is made.

"That's very bad for the reputation of the organisation, and it's distracting for those alleged to have taken part."

And money can be saved. Compensation for hurt feelings alone can range from about �300 up to �20,000.

Mr Hyde...

blurts out his inner-most feelings to anyone in a short skirt

Often the problem is not everyone can agree on what constitutes harmless fun.

In September, a senior lecturer resigned from the University of Wales after bosses launched an investigation into complaints he had told sexy jokes at a Christmas party.

And Jim Hodkinson, former head of the fashion firm New Look, was fired in May after patting a colleague's bottom at an industry party.

Getting staff to stay

But a good office party should be about helping retain staff, rather than losing them, says Mr McCourt, who runs party co-ordinators Awesome Events.

Don't take the bonding exercise too far

His job is to help appreciative employers pull out all the stops.

This year, the company is working on a Moonraker night at Pinewood Studios, where the classic 007 film was shot (and the guests will sip martinis - shaken, not stirred), and a Stars in Their Eyes karaoke party.

No matter how over-the-top the official arrangements, Mr Warnock says decency rules still apply.

The "hey, it was the office party, lighten up!" excuse does not stand up, Mr Warnock says.

"It's just too dangerous to assume that, as in the past, people who are offended tend put up with it - they're not anymore."