Income tax

I am currently a uk resident but in septmber I plan to move to Spain where I will be resident for more than 183 days a year, however I will continue to undertake work with a uk company. I may also have to spend more than 91 days in the UK which I think qualifies me as a UK tax resident. The salary will be less than 22000 euros a year. To which country will I need to pay my income tax?
Thanks,
Ben