In October 2016, when Theresa May had Brexiteers purring and Middle England curled up in her lap, her government unveiled the Great Repeal Bill. Despite the name, the bill was really a "tidying up exercise", designed to enshrine EU laws into British law before the real business of Brexit got started.

But the Great Repeal Bill attracted its critics - and not just the woman who took the government to court, Gina Miller, who accused May of "acting like a power-crazed monarch". The Hansard Society raised concerns about the use of Henry VIII clauses, which allow the government to by-pass Parliament (more about that later).

Then came the snap election. After the Conservatives lost their majority, a humiliated May replaced the Great Repeal Bill with the EU Withdrawal Bill. As my colleague Stephen wrote in July, there is very little difference beyond the name change.

In the early hours of 12 September, MPs voted for the bill to go through to the second reading stage by 326 to 290, after Remain-backing Tory MPs fell in line with the government and a small number of Labour MPs rebelled against orders to oppose it.

So what do you need to know about the Great Repeal Bill EU Withdawal Bill? (Apart from the whole big picture about leaving the EU of course).

1. The Henry VIII powers are still there

Named after the larger-than-life Tudor king, these powers date back to the days of monarchical dominance and allow the government to tinker with legislation while avoiding parliamentary scrutiny. (You can read more about Henry VIII clauses here).

The government’s bill is in effect one of these power grabs, because it would allow the government to “adapt legislation” so it “functions effectively post Brexit”, in the words of the House of Commons library.

This is the main reason the Labour party has given for opposing the government's bill. In a statement, it said: “Labour fully respects the democratic decision to leave the European Union, voted to trigger Article 50 and backs a jobs-first Brexit with full tariff-free access to the European single market.

“But as democrats we cannot vote for a Bill that unamended would let government ministers grab powers from Parliament to slash people’s rights at work and reduce protection for consumers and the environment."

2. There are specific concerns around consumer protection and workers' rights

As the Labour statement suggests, the party might accept Brexit, but it's a very particular kind of Brexit. It is not alone. The consumer group Which? commented: “The use of Henry VIII powers is largely incompatible with the principles of accountability, effective scrutiny and consumer input.”

As for the World Wide Fund for Nature (WWF), it cautioned that over-reliance on delegated legislation would be “worryingly undemocratic, especially when dealing with the vast range of environmental protection measures”.

While the government says it will protect workers' rights, the trade unions are particularly concerned about the future eroision of some hardwon gains, particularly those around holiday pay.

3. The opposition is against it

As well as Labour's opposition, the third biggest party, the Scottish National Party will oppose the EU Withdrawal Bill, as will the Lib Dems. But unless there are some surprise rebellions from the Tory party, May is still likely to be able to force it through. That's thanks to the Brexit-backing Democratic Unionist Party, which signed up to support the Tories on key measures in return for a £1bn sweetener for Northern Ireland.

4. Even Tory MPs want changes

Although Tory MPs voted with the government, some are already planning to put down amendments to the bill on its second reading. Like the opposition, they are worried about a power grab.