As a UK resident, you are liable to tax in the UK, on all of your world wide income, even if you do not bring it into this country. Foreign income is criteria for completing a self assessment tax return for the tax year in which the income arises. You would need to declare your foreign employment income and claim a credit for any foreign tax deducted from the income, on SA106 'Foreign' page and submit with the main tax return SA100 and any other relevant supplementary pages. The deadline for paper tax returns is 31 October and 31 January for online tax returns:
Above link will help you with self assessment and how to file your tax return online.