The Independent approves of what John Bercow, the Speaker of the House of Commons, said about Donald Trump, but we oppose – not quite to the death, perhaps – his right to say it.

Like him, although we value the United Kingdom’s relationship with the United States, we would prefer that President Trump not be accorded the special honour of an invitation to address both Houses of Parliament in Westminster Hall. Mr Bercow’s sentiments, in saying “our opposition to racism and to sexism, and our support for equality before the law and an independent judiciary are hugely important considerations”, were quite right. But he was wrong to express them in public in this way.

The Speaker is supposed to be an impartial and bipartisan presiding officer. He seems to have fallen victim to linguistic confusion, mistaking “speaker” for the word “spokesperson”. His job is not to speak on behalf of MPs collectively on political matters. That is why we have political parties, and a government and an opposition. The Speaker's job is to facilitate debate, not to take part in it.

Lord Fowler, the Lords Speaker, was quite right today to admonish Mr Bercow gently for his presumption. As Lord Fowler said, invitations to foreign leaders are usually discussed by the speakers of the two houses of Parliament in an attempt to seek consensus. By expressing his personal view, Mr Bercow has short-circuited that consultation and in effect vetoed the invitation to the President.

The objection to Mr Bercow’s showboating is not that Mr Trump will now give the Palace of Westminster a miss. It was never likely that an invitation would be issued, given the feelings of MPs and peers. The problem is that Mr Bercow has damaged the machinery of democracy because he could not resist advertising his own liberal credentials.

The Speaker’s standing with Conservative MPs was already low, but by launching what was in effect a political attack on the Prime Minister he has forfeited any right to their respect.

Theresa May may have miscalculated in rushing to be the first foreign leader to meet Mr Trump, and there are many people who have expressed their opposition to the idea of the President making a state visit to this country – including the 1.8 million ordinary citizens who have signed a petition to that effect. There was no need for Mr Bercow to add his signalling to this festival of virtue. All he has done is open himself to the charge of hypocrisy, as he has previously welcomed Xi Jinping, President of totalitarian China, and other authoritarian leaders to the Palace of Westminster.

The Speaker’s misjudgement is a pity because it further obscures many of the important reforms over which he has presided. Since he was dragged to the chair in 2009, backbenchers have been given a greater role in the Commons. Ministers are summoned to the Chamber more frequently to answer questions. He has allowed Prime Minister’s Questions to overrun its allotted 30 minutes so that more MPs can hold the head of government to account.

Mr Bercow may privately congratulate himself on showing his independence of Government. He and David Cameron patently lacked any respect for each other. But there is a world of difference between independence from Government and political opposition to it.