Allowable Hospitality / Entertainment?

Hello,

I have a client, currently a sole trader, who trains employees (in a number of Health and Safety matters for example) of a large number of unrelated companies up and down the UK.  Most of the training sessions takes place in classrooms where my client would pay for and provide light refreshments and biscuits to his pupils.  Are such expenses allowable for tax?

Also, at the end of most sessions, he'll take one or two of the bosses out for dinner, before he'd depart and drive home for the evening.  Bearing in mind that such expense would often be incurred a considerable distance away from his home (typically, at least over 60 miles away), could my client claim his proportion (only) of the dinner expenses as allowable subsistence (the rest being treated as entertainment, not allowable for tax purposes)?

Any comments would be appreciated.

Thanks.