You have given your statutory four weeks notice, so you can leave on the day you wish. You can also take your holiday during the notice period as planned. Unless it clearly states in your contract of employment that holiday cannot be taken during a notice period, there is nothing your employer can do about it. If you take it, what are they going to do? You are leaving anyway so they can't sack you. The worst thing they can do is give you a verbal warning. Take your holiday and have a good time, totally ignore their threats, they are just trying to frighten you. If your employer refuses to pay holiday pay that you are entitled to, take them to an industrial tribuneral. They haven't got a chance in hell of winning, the court will back you all the way as it is a legal requirement for them to pay you pro-rata 20 days per annum. Do check your entitlement first though, because if you haven't worked a full year you will only get the relevant entitlement for the period you have worked during the year. Don't forget you are only going to work two weeks of your notice. I wouldn't suggest as one person did to sticking two fingers up to them. It is not worth leaving your employment on bad terms, as you may want your employer to give you a reference at some future date. Keep the peace, and walk away gracefully.