You are exempt from UK taxes if you are out of the country and employed abroad for a full tax year April 5 to April6.In theory your 2 year deal could run for half a tax year then a full tax year and then half a tax year, if you see what I mean. You will hen be liable for UK tax on the two half years. And dont forget tax is payable on the benifits as well as salary, so if you get housing and car allowance, which in my case almost doubles my salary, you will have to pay UK tax. See the taxman and a good accountant before leaving the UK. Remember the tax laws for people working abroad out of the UK changed in May 1998, dont get caught it can be expensive.
SEE AN ACCOUNTANT BEFORE YOU LEAVE.