[Technologist]

…..;
The BBC explicitly stated this evening what its issue was with Lineker's actions: "We have said that he should keep well away from taking sides on party political issues or political controversies." This situation, in the BBC's own words, has nothing whatsoever to do with the specifics of his comments - the BBC has made it plain that it's simply not happy with Lineker expressing opinions with political implications. That is the issue here, and the BBC couldn't have been clearer in explaining that. 

And the guidelines for all who “work” for it is very clear …
Particularly for what OFCOM deems controversial
www.bbc.co.uk 
Section 2 in particular …..

And it’s general applicability
“ Everyone who works for the BBC should ensure their activity on social media platforms does not compromise the perception of or undermine the impartiality and reputation of the BBC, nor their own professional impartiality or reputation and/or otherwise undermine trust in the BBC.”
And
“ The extent to which a non-staff member, contributor or presenter is required to comply with the Editorial Guidelines will be set out in the BBC’s contractual relationship with them.”