A report in the Guardian today examines the legal position on conference and course delegates who behave badly.

Following the well-publicised case of the Railtrack employees brought to book after a drunken away weekend, consultant Tricia Jackson says that it's difficult to legislate for employees behaviour during the evenings when the time is effectively their own.

Some employees who have been accused of bringing the company into disrepute by their antics have been dismissed successfully on these grounds, but problems arise when there is no clear guidance on behaviour. If employers provide free bars, for example, it's difficult for them to be heavy handed with those who've taken advantage of it.
Some companies are keen to encourage socialising with colleagues as it can be valuable for team-building.

The message seems to be to have a clear policy drawn up about behaviour away from the office.

It's worth having a look at The Employment Rights Act 1996 for starters if drawing up a policy in this area - there are too many employment law websites available to list here, but www.lawrights.co.uk is worth looking at for information on defining unfair dismissal.