President Donald Trump doesn't deserve the honor of a state visit to the United Kingdom, a top British opposition lawmaker told CNBC Tuesday.

Trump is on the second day of his state visit to the U.K. where is meeting with royalty, business leaders and outgoing Prime Minister Theresa May.

Speaking to CNBC's "Street Signs Europe," Emily Thornberry, the shadow foreign and commonwealth secretary for the opposition Labour party, said the U.S. president did not represent American principles or morals.

"My point is that Donald Trump does not encapsulate those values. In fact, I think he is trying to lead America backwards." A spokesperson for the White House was not immediately available for comment when contacted by CNBC.

Thornberry said her stance was not anti-American and that she would travel Wednesday to remember "all those brave American boys" who lost their lives on the anniversary of the D-Day landings during World War II.

Thornberry argued that those soldiers came over to Europe during that war to protect values that Trump does not himself adhere to. She said dealing with him as a president did not mean having to afford him a celebratory welcome.

"My objection is him getting the honor of a state visit," added Thornberry before saying the U.K. had been weak in its dealings with Trump and had "bent over backwards" to accommodate him.