I run an office of about 60 people. Last month I decided that I'd take everyone on a company trip to Alton Towers. I try and do something recreational each year as I find it's good for morale and slightly less of a contrived teambuilding exercise than building rafts.

We leave on a Thursday afternoon, everyone has their own hotel room, we have a day in the park and then head off at 5pm to arrive home at 10pm.

About 10% of people are saying they're not going. I haven't looked into the reasons for all of them but I know that at least one of them isn't going because they don't like 'organised fun'.

It irritates me a little that some people have this attitude, but I was expecting it. The question I have for you folks here, is what happens to the people that stay? I don't want to give them the day off, because I don't want to sanction that as an option. Equally, I don't want them working in the office because next time I organise an event I don't want people to think that they've got an option of going on the event or working in the office.

On the other side, I'm not going to force someone to go.

The solution I've come to is that I ask people not going to take the day off as holiday. Is that reasonable? Is that legal? The employment contract states that I can ask them to work in a location other than their usual location from time to time, and this trip is as important to me as an off-site training course.

I'll be presented with different reasons for not going.

1. They don't like 'organised fun'. Bad excuse.
2. They have to feed their pets. Weak excuse.
3. They find events such as these socially awkward. I'm sympathetic, but ultimately not a good excuse.
4. They have a wedding reception on the Friday night. Reasonable excuse.

Where do I stand legally? Where do I stand morally? Any advice would be welcome.