I fully supported Labour’s three-line whip to vote to trigger article 50 last week. Our union campaigned vigorously to remain in the European Union but we respect the result of the referendum. Had Labour voted to block article 50 at the first hurdle, it’s effect would have been to give millions of voters the proverbial two fingers. Let’s face it, many people voted leave because they felt our political class no longer speaks for them. A vote against starting the process to trigger article 50 would have gone a long way to proving their point. However, no one voted for “Brexit at any cost, which is why the amendments tabled by Labour’s front bench are warmly welcome”.

The 1.2 million-plus British people living elsewhere in Europe and the 3.3 million EU citizens who have made their homes in Britain should not be used as pawns in Tory Brexit negotiations. Across the Labour and progressive movements, irrespective of the position taken during the referendum, there is now overwhelming support for Labour’s amendment on this issue.

Labour is also right that Brexit can’t be used for our country to become a bargain-basement tax haven where workers’ rights, environmental protections and public services are destroyed in a deregulatory bonfire as we rush to seal new trade deals. The signs are already ominous. Theresa May’s cuddling up to Donald Trump is likely to result in a trade deal that will make the defeated Transatlantic Trade and Investment Partnership look munificent. Make no mistake, our NHS and other vital public services will be put up for auction to the highest bidder.

The Tory cries of “take back control” really stick in my craw. Arch-Brexiteer Chris Grayling could not use these buzzwords enough during the referendum campaign. Funny how, since becoming transport secretary in July, he has allowed the Italian national railway to join the Dutch, German and French state in running our train services. I doubt even many conviction leave voters share a notion of “take back control” that allows even more EU countries to make money at the expense of our UK rail passengers and taxpayers. So Labour is absolutely right to demand any Brexit deal must be brought to parliament to be accounted for before it’s signed off.

‘The Tory cries of ‘take back control’ really stick in my craw. Arch-Brexiteer Chris Grayling could not use these buzzwords enough during the referendum campaign.’ Photograph: Reuters

Which brings me to Labour’s amendment dealing with access to the single market. My union has strongly objected to the deregulatory impulse of Brussels. As I told our union’s conference last year, the vote on the EU referendum was never a choice between a utopian socialist republic of our dreams and the EU as it stood. The choice we got last June was between the flawed status quo or the prospect of a Tory Brexit led by market fundamentalists. Unsurprisingly, our conference voted comfortably for our union to campaign for remain.

I hope Labour’s amendments are accepted, as they will bring greater clarity and democratic scrutiny to the Brexit process. But the question Labour MPs must ask themselves before they walk into the lobbies tomorrow is: what is their plan if the amendments are defeated? Having set out their stall, they must not then rubberstamp legislation that counters Labour’s shared values. There is no case for a Tory Brexit at any cost. Labour is, after all, the opposition.

I realise feelings on this issue are heated, and understand the political toxicity around free movement of people because of the need to deal with a strong Ukip challenge in many areas; but sometimes in politics you just need to do what is right.

The idea of the Tories deploying the threat of mass deportation of EU families living here as a negotiating ace is unacceptable. That alone should be enough to prove why waving through an unamended Tory Brexit bill would be a big mistake. If Labour’s amendments fail, then the facts change and our Labour party must face that reality, do the right thing and whip our MPs into voting against an unamended Tory Brexit. If it doesn’t, MPs must themselves do the right thing; they must vote against it anyway.