But if they came to Parliament Square in the hope that their presence might persuade parliamentarians to resolve the Brexit crisis by backing Theresa May’s divorce deal, they were to be disappointed: the prime minister was defeated for the third time by 58 votes: 28 of her own eurosceptic MPs voting with Labour and opposition MPs to reject her withdrawal treaty, and with it the certainty of leaving the EU with a deal on 22 May.
They perhaps hoped that by rejecting the deal, Britain will leave with no deal on 12 April – the date the UK is scheduled to leave the EU with or without an agreement.
But ministers from the cabinet downwards believe that this ship has sailed.
As the prime minister herself said at the dispatch after her defeat: “The House has been clear it will not permit to leaving without a deal, so we have to find a way forward.”
Describing the implications of the decision to vote her down as “grave”, the prime minister went on to say “we are reaching the limits of this process on this House”.
Everyone read one thing only into that remark; the prime minister could be paving the way for a general election to break the impasse.
Less than an hour after Mrs May was defeated, her party chairman Brandon Lewis tweeted a new social media post – “Labour just voted to stop Brexit” – which looked very much like a general election slogan.
The Conservatives are deeply opposed to a second referendum or a “confirmatory vote” on Mrs May’s deal, but the routes out of the Brexit impasse are narrowing.
And as they do, Number 10 might feel it has no option other than to gear up for an election that pits the Tories as the party of Brexit and Labour as the party of Remain. A second referendum by proxy.
Speaking to ministers and government insiders on Friday afternoon, it was clear that confusion reigned as to what the prime minister should do next.
On Monday, MPs will vote again on up to eight different Brexit options, testing to see if there is a parliamentary majority for a second referendum or a softer Brexit, as opposed to Mrs May’s deal.
As MPs vote on other options, Mrs May’s team are assessing whether the prime minister can bring back her deal for the fourth time – should the Speaker allow it.
The government could perhaps position it as a run-off between the successful alternative of the indicative votes and Mrs May’s deal, but government sources admit it will be “hard to bring back with the Speaker”.
This is why the options are narrowing. Mrs May has stuck rigidly to her Plan A for months in a war of attrition with her party. She has reduced the opposition from 230 to 58 votes, but still can’t get it across the line.
Now parliament is determined to have its say.
But even as MPs prepare to try to force a softer Brexit upon the prime minister – in the form of some form of customs union or single market deal – ministers are privately warning that such an alternative simply can’t be adopted by the prime minister.
“If she goes for a customs union Brexit and a long extension, half her cabinet will threaten resign. If she ignores the will of parliament, the other half of her cabinet will threaten to resign. Either way her government becomes untenable.”
Cabinet sources think the most likely option now is that the prime minister will have to return to Brussels for an emergency summit on 10 April and request that Brexit be delayed beyond 12 April.
This then tips the UK into having to participate in the EU parliamentary elections – an anathema to Mrs May and the majority of the party.
At that point, the prime minister might announce her departure to make way for a successor and a possible general election.
The truth of it is as MPs travel home for the weekend, no one really knows what the next chapter in the UK’s Brexit saga holds, and it won’t be resolved on Monday.
But what Friday’s defeat amplified yet again, is the limits of a divided parliament and a minority government to get anything through. And we all know what follows from that.