The House of Lords should be turned into a tourist attraction full of stuffed peers dressed like "demented Santa Clauses", an SNP frontbencher has joked.

Pete Wishart, the party's Commons leader, railed against the unelected upper chamber which he labelled an "undemocratic disgrace" which is "stuffed full of cronies, donors, placemen, former MPs and failed members of Parliament".

The SNP has called on the Government to abandon plans to cut MP numbers from 650 to 600 until it tackles the ballooning size of the Lords which has more than 800 members.

Mr Wishart said the UK had no right to "lecture the developing world" on democracy while the Lords was maintained in its current form.

Intervening, Hannah Bardell, the SNP MP for Livingston, said: "Do you agree with me that there are countries around the world that we can look to to learn from, countries such as Australia who ironically enough have chambers that are based on this House but have managed to leap ahead and have elected chambers and actually in the Queensland parliament have abolished their upper chamber and now it is in fact a tourist attraction.

"Do you agree with me that if we do not make progress we are going to fall behind in the world in terms of global democratic process?"

Mr Wishart prompted laughter as he replied: "You make a very good point and I'd love to see that place as a tourist attraction.

"We could stuff some of them full so we could see what they were like.

"They are all dressed like demented Santa Clauses.

"It would be fantastic. Maybe a winter, Christmas fantasy or something?"

Mr Wishart hit out at the make-up of the Lords which includes numerous seats for bishops.

He said: "This place, this legislature, is the only legislature in the world that has a place reserved for clerics other than the Islamic Republic of Iran."

Meanwhile, he said the "ultimate horror" was the number of Liberal Democrat peers.

He said: "We still have 104 Liberal Democrats.

"Roundly rejected by the electorate, they are kept alive in that crypt down there on a political life support system."

The SNP's motion, tabled as part of an opposition day debate on House of Lords reform and the size of the House of Commons, called on the Government to come up with plans to cut numbers in the Lords and for overall reform of the unelected chamber.

Mr Wishart also attacked the "deference" shown to peers which he likened to the popular TV show Game of Thrones.

"I actually looked for the House of Lords TV channel the other day and I came across the fantasy adventure Game of Thrones instead," he said.

"I was listening to some of the language that was being used and it struck me that the House of Lords is so like Game of Thrones without all the dragons, beheadings and the proper bending of the knee.

"That is how ridiculous that institution is down the road."

On the issue of democracy, he said: "In describing this place, in all its undemocratic horrors we still have the audacity to lecture the developing world about the quality of their democracies.

"We have the gall to tick them off about corruption, about patronage and cronyism when we have a chamber filled down there which is appointed by a prime minister."

Mr Wishart concluded: "The House of Lords is a national embarrassment. It's something that should shame the country. It needs to be reformed, it needs to be looked at."

Deputy Commons Leader Michael Ellis appeared to dismiss any prospect of reform in the short-term, telling MPs: "We accept the size of the House of Lords is something that needs to be looked at, but there are priorities. It is not a priority in this Parliament.

"Attempts were made in the last Parliament, and this Parliament has pressing business, so the reform of the House of Lords, while its recognised the size is large, is something that we need to deal with in due course, and preferably by consensus.

"There are many different views on what form the House of Lords should take.

"Without any consensus, there's no practical possibility, frankly, of taking such reform forward."

Mr Ellis added that reforms in the previous Parliament meant Lords could now face expulsion, while the House had cut its running costs by 14% in real terms since 2010.

The Lords also had some 400 fewer peers than it did in 1998, Mr Ellis said.

But Tory backbenchers Dan Poulter and Philip Davies also urged the Government to take action, in questions to Mr Ellis.

Dr Poulter said: "He's right to talk about the importance of democratic legitimacy, but would he accept it's democratically illegitimate to have hereditary peers sitting and having any say in our democratic process?

"It is actually something that gets in the way of the legitimacy of some of his other arguments, when that very simple change could be put forward and could actually help him carry through some of the argument he's making in terms of constituency equalisation."

Mr Davies added: "Will he commit to reducing the size of Government by the same proportion he's trying to cut the number of MPs, because if he doesn't do that, it would actually give the Government more control over Parliament, which to many of us is unacceptable.

"If he reduced the size of the number of ministers, he'd save a bit more money as well."

Former justice secretary Michael Gove accused the SNP of throwing a "political dead cat on to the table", a tactic designed to divert attention away from more pressing issues.

Explaining the idea, he said: "Whatever the controversy that's been raging beforehand, people suddenly say "Oh my God, there's a dead cat on the table".

"In this debate, the House of Lords, perhaps appropriately for an ermine-clad chamber, is the dead cat. They wish to divert attention away from a number of issues.

"The reason why the SNP is raising a constitutional issue, whether it's the House of Lords or any other constitutional issue is that they cannot talk about bread and butter issues because their record is so appalling."

Attacking the party, he added: "The real thrust behind the SNP's position is ultimately the institutions that bind this United Kingdom together, the institutions that are a focus for loyalty in this United Kingdom, like the monarchy, are opposed by them because of their single-minded pursuit of separation and independence come what may.

"If they object to unelected figures wielding power that makes them unaccountable and out of touch, why do they not object to the existence of the European Council in its current form? The answer again is because separation is all they are interested in."

Shadow cabinet office minister Ian Lavery said Labour would support the SNP motion, adding that the Government had "many questions to answer on the issue of democracy".

He urged the minister to give a guarantee that Tory MPs who lost their seats in the boundary changes would not be "stuffed in the House of Lords as a solution that the Conservatives face".

The SNP's motion was defeated by 278 votes to 245, majority 33.