Members of the UK’s House of Lords arrived at Parliament Wednesday with sleeping bags as they prepared for a marathon session to debate a bill that would stop Prime Minister Boris Johnson from leaving the EU without a divorce deal, according to reports.

With the measure passing the House of Commons, supporters of the PM in the upper chamber are expected to filibuster the bill by insisting that every amendment — more than 100 — be fully debated in an effort to drag the process out until Parliament is suspended next week, the Independent reported.

That means that the debate could continue long into the weekend, with supporters of the measure — Labour members, Liberal Democrats and many Conservatives — planning to keep voting until the job is done.

According to the outlet, the members came prepared for the long haul — armed with sleeping bags, toothbrushes and spare clothes.

Unlike the House of Commons, where amendments can be grouped or voted on in bunches, the Lords debate each amendment individually.

“Time is their weapon, numbers are ours,” one senior pro-bill peer told the BBC.

The bill would force Johnson to ask the EU to delay Brexit until Jan. 31, unless he can pass a deal on the terms of the exit by the end of October.

Twenty-one of his fellow Conservatives backed the measure Tuesday — and the rebels were promptly kicked out of the party.