Third reading is the final opportunity for MPs to pass or reject the whole bill. It normally takes place immediately after report stage and any Legislative Grand Committee. There is usually up to an hour for the debate, although some of this time might be used up by any votes at the end of report stage.
In the House of Commons, you can’t amend the text of the bill at third reading (unlike in the House of Lords, where amendments can be made at third reading). If you disagree with the content of the bill, you can submit a reasoned amendment setting out why. The Speaker will decide whether to select your reasoned amendment for debate. Reasoned amendments to third reading are rare.