I've worked at the same company for almost 5 years, small business with me and one other employee. I work 16h a week, but I work alone and never see my employers. Two bosses (husband&wife) both in their 60's, pretty naive about employment law, pensions etc.
I've been told they are closing the section of the business I work in in April. Assume ok fine - redundancy. Mention this to bosses and they seem shocked ("we have to give you lots of money?!") its £700 so substation but not loads. They earn £120k+ combined yearly.
Last week I got a call from boss1, they have checked through their security records for past 3 months and can see I have been consistently late. boss1 says it adds up to almost 8h all together. I apologise and ask to be sent the records - doesn't make it much better but it adds up to 4h total lateness in 3 months (varies 1-15mins a day, traffic is the cause) the other employee is similar, however apparently she has not been approached.
Boss1 says I have two options - either work a whole day for them for free to help close down the business, or I have to repay every instance of lateness in the past 5 years (says they will trawl the records) she also said if I chose to work the free day, they want to have a nice time and we need to be civil and have "some fun with it" 
Now, the less time spent with these people the better imo. I just want to get it over with, get my redundancy pay and go so I am keen not to work the free day. Can they really enforce the "lateness charge" they are proposing? Sometimes I work through my lunches, sometimes I stay late, sometimes I come in early so I don't see that they can fairly calculate this - plus surely its not lawful.
Help, advice? Thanks