The tirade came as unelected peers debated further amendments to the Government’s Brexit Bill on Tuesday.
Despite the bill passing with ease in the Commons, Lords voted in favour of adding a clause of guaranteeing EU nationals’ right to stay in the UK last week.
George Galloway branded the House of Lords 'Parasites'
Please don’t be lured into supporting this bloated class of parasites
The government is bracing itself for a further defeat on Tuesday, when Opposition, cross-bench and some Tory rebel peers look to secure a “meaningful vote” for MPs at the end of the EU talks.
Although it’s likely the amendments will be rejected in the Commons next weeks, critics have demanded the Lords be abolished if it is seen to be trying to derail the Brexit process.
Those calls have been backed up by Galloway, who warned his talkRADIO listeners not to be “lured” in to supporting the unelected chamber.
Lords will vote on the Brexit Bill on Tuesday evening
He fumed: “What possible justification can there be for an unelected House of Parliament to defy not only the elected House of Parliament but to deny the British people in a referendum who’ve already made the decision to leave?”
“Please don’t be lured into supporting this bloated class of parasites, almost every one of them, few exceptions, it’s time to clean the Augean stable of British democracy and get rid of them."
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A Remainer bid to secure a second EU referendum at the end of Article 50 talks was rejected on Tuesday.
All the pictures from Brexit Bill Tuesday Tue, March 7, 2017
Theresa May is facing a second defeat on her Brexit bill Tuesday as the House of Lords votes on another change which would give parliament the final say on leaving the EU
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Archbishop of Canterbury, Justin Welby, speaks in the House of Lords Chamber at the start of the third day of The European Union (Notification of Withdrawal) Bill
The proposed legislation was put forward by Liberal Democrat Lord Newby, along with Labour peer Lord Hain and Conservative peer Baroness Wheatcroft.
But, the upper chamber overwhelmingly rejected the demand, with 336 voting against and only 131 supporting it.
Having failed to secure the amendment, Liberal Democrat peers will now vote against the legislation in its third reading later this evening.
Speaking after his defeat, Lord Newby said: "The people started the process of Brexit and it is only right that they are given a say on the final deal.
“Today the Government have confirmed that the Brexit deal will be finalised behind closed doors in Westminster. This is not accountable, this is not democracy and that is why the Liberal Democrats cannot support this Bill.
“Theresa May is driving Britain towards a hard Brexit which wasn’t on the ballot paper and which no one voted for. The Liberal Democrats are the real opposition to this Conservative Brexit Government.”