As written at The Telegraph by Laura Hughes in Brexit timetable: What happens next in Britain's exit from the EU?, Brexit has in fact quickly and easily passed the House of Commons:
"The European Union (Notification Of Withdrawal) Bill will allow the Prime Minister to invoke Article 50 of the EU treaties and was backed by 498 MPs to 114, a majority of 384, at second reading in the House of Commons, its first stage."That Bill goes to the House of Lords for debate:
"European Union (Notification of Withdrawal) BillWe have problems with the all-encompassing wording of the bill in its statement that "(2)This section has effect despite any provision made by or under the European Communities Act 1972 or any other enactment."
A bill to confer power on the Prime Minister to notify, under Article 50(2) of the Treaty on European Union, the United Kingdom’s intention to withdraw from the EU.
Be it enacted by the Queen’s most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same, as follows:—
1 Power to notify withdrawal from the EU
(1)The Prime Minister may notify, under Article 50(2) of the Treaty on European Union, the United Kingdom’s intention to withdraw from the EU.
(2)This section has effect despite any provision made by or under the European Communities Act 1972 or any other enactment.
2 Short title
This Act may be cited as the European Union (Notification of Withdrawal) Act 2017."
The core idea of requiring an Act of Parliament to permit triggering of Brexit is not only to accord by the demands of representative government but also to make sure that all rights and obligations previously in force as a Member of the EU have been examined thoroughly and handled in accordance with the laws in effect.
Obviously, the UK has sovereign power to leave the EU, but the process can not be helter-skelter in terms of legal analysis of the status quo, the obligations that must be fulfilled, and how they are to be fulfilled.
For some of the complex problems involved in leaving the EU, take a look at The Great Repeal Bill in The Law and Brexit at the Harvard Law School Forum on Corporate Governance and Financial Regulation.
See The Telegraph's Brexit timetable: What happens next in Britain's exit from the EU?, for a schedule of anticipated dates of action.
We expect the peers of the House of Lords to be critical in their debate of the Brexit Bill.