There are times when politicians simply have to stand up and do the right thing. And there are times when it is also the role of the press to hold them to it. Today is one of those primary-coloured times. This newspaper has backed electoral and political reform, including reform of the House of Lords, for more than a century. So have Labour and the Liberal Democrats; both have proud records. That is why the right thing for members of parliament from both parties is to support the government's reform plans for the House of Lords and to vote for a timetable that gives reform its best possible chance of passing through parliament in this session. All of us say we are still committed reformers. So let's prove it.

That means that MPs who regard themselves as Lords reformers – and they were all elected on manifestos committed to reform – must recognise a lifetime opportunity when they are given one. That therefore also means putting Lords reform above the partisan squabbling which impresses no one else but to which all the Westminster tribes are increasingly addicted on every issue in politics. MPs on all sides need to lift their sights. They need to have a sense of history. And they need to be aware that they are being watched and judged not just by the living public but by the ghosts of the reformers who went before, and in whose footsteps they are privileged to tread.

Seen from outside Westminster, the question today is much clearer than too many politicians seem to pretend. It is whether Britain can at last move decisively away from having a parliament with a wholly unelected second chamber and march across the watershed towards democratic law-making. It is about putting the people firmly in charge of their own politics. That is a noble cause, even in a time of economic preoccupation. It ought to be something which all parties, including the Conservatives, can support.

Two things need to happen in the Commons for that watershed to be crossed. The first is for the government's Lords reform bill to get a second reading. The bill is certainly not perfect. It does not envisage a wholly elected second chamber. It retains places in the Lords for interests, notably the Church of England, which should not be represented as of right in parliament. The bill will certainly need to be amended and compromises made. But it is based on the principle of election, it does something to address the imbalances in the current upper house, and it is clear about the supremacy of the House of Commons. It is a huge step towards the fully elected parliament that no one who considers themselves a democrat should oppose and that generations have striven to achieve.

The second thing that needs to happen is to vote for a Commons timetable motion which ensures that the bill can get through all the stages of its parliamentary passage in the time available. All big constitutional bills require this kind of treatment. That is why outright opposition to programming of this kind is ultimately specious and deceitful, a tactic masquerading as a principle. The only question is whether the programme motion is a reasonable one. That is a matter of management and talking between the parties. A compromise has to be struck all the same – perhaps improvements can be made even down to the wire tonight. In the end, though, any programme motion is better than none at all.

If Labour cannot bring themselves to agree such a motion, then they are not being true to their history as a party of reform. Neither dislike of the coalition nor frustration at its proposed timetable justifies going into the lobbies with Tory MPs whose only concern – as they made clear in a torrent of reactionary interventions and speeches yesterday – is to preserve the Lords as it exists today. To vote in a way which effectively abandons the bill to filibuster and delay would be a shameful decision for Labour, with its fine record, ancient and modern, on Lords reform. Keir Hardie and Robin Cook would turn in their graves.

• This article was amended on 13 August 2012. The original said that only the UK and Lesotho had a wholly unelected second chamber. Other countries have second chambers that are wholly appointed. The distinction the UK shares with Lesotho is having a system that allows some members of the second chamber to inherit their office.