Huw Edwards has defended claims he endorsed a Labour-supporting tweet saying he was backing the NHS.
The BBC newsreader was criticised by Conservative David Davis for liking a post that ended in a message "Vote Labour for the National Health Service".
He was also said to have liked other tweets including one questioning Boris Johnson's claim that his Brexit deal is good for Northern Ireland.
But the prominent broadcaster wrote on Twitter : "Yeah I liked a tweet which seemed to be a celebration of our wonderful @nhs —apologies for not watching right to the end.
"But apologise for supporting the NHS? Never. EXCLUSIVE — my family owes it a huge debt."
The pro-NHS video which Hugh liked features comedian Rob Delaney, it apparently includes the claim the Tories want to privatise the NHS and sell it to the US.
The 2 minute 18 second video includes the slogan "Vote Labour for the National Health Service" after 1 minute 53 seconds.
David Davies told The Sun BBC staff should "keep their political opinions to themselves".
He said: “I’ve known Huw for a long time and he’s been very professional with me but this is a disappointing lapse in judgement on his part.
“He knows the BBC’s highly salaried members should keep their political opinions to themselves.”
BBC guidelines reportedly say that staff must not "state or reveal how they vote or express support for any political party".
They continue: "Express a view for or against any policy which is a matter of current party political debate.
“Advocate any particular position on a matter of public policy, political or industrial controversy, or any other ‘controversial subject’.”
But a BBC spokesman told The Sun that “likes and retweets are not the same as endorsements.”
