The double taxation treaty between Belgium and the UK has been amended. This is the original treaty:
http://www.hmrc.gov.uk/taxtreaties/i...elgium-dtc.pdf
Which has been amended with the following, effective since december 2012:
https://www.gov.uk/government/upload...35961/8549.pdf
As an employee it is now: pay tax where you live in stead of pay tax where the effective place of management of the company you work for is based.