Following an historic win for the Conservative Party, we now know the shape of the new Parliament. The Government is expected to remain largely unchanged, although there will be some minor changes to the line-up of ministers, with a major reshuffle not expected until next year. The new Parliament will assemble on Tuesday 17 December, in accordance with the Royal Proclamation of 6 November. The new parliamentary session begins officially with the State Opening of Parliament, currently expected on the 19 December, at which the Queen's Speech will set out the Government's legislative programme. This is usually followed by six days of debate in both Houses. Given that the time between the new Parliament assembling and any Christmas recess will be a matter of days, it is unlikely that the debate will be concluded until after Christmas, and it may be replaced entirely by consideration of the Withdrawal Bill, with Parliament even sitting at the weekend. New MPs will need to make their maiden speeches and the Queen's Speech debate normally provides the first opportunity for new MPs to do so. The first Government Bills are also put before Parliament following the Queen's Speech.
The House of Commons and the House of Lords will sit before State Opening, during which time the election of a Speaker of the House of Commons will take place and MPs and peers take the oath or affirmation. If the Speaker in the previous Parliament has been returned as an MP, and has indicated a wish to continue in post, custom and practice indicates that such an election is purely formal. Therefore, Sir Lindsay Hoyle, who was elected Speaker at the end of the last Parliament, will almost certainly be confirmed as Speaker. The Speaker notifies the House of the arrangements for the election of the Deputy Speakers, usually three in number, which takes place by secret ballot, but may not take place immediately.
Once the Speaker has taken the oath or affirmation, MPs come forward in order of seniority to swear or affirm at the despatch box. Each MP then signs the 'Test Roll' which is kept by the Clerk of the House of Commons and is introduced to the Speaker by the Clerk of the House. The initial period of swearing in lasts about two hours and most MPs are sworn on the first day, although the Commons will also meet for swearing-in after this. MPs cannot take their seat, speak in debates, vote, or receive a salary until having taken the oath or affirmation. MPs elected for Sinn Fein refuse to swear or affirm and therefore can take no part in parliamentary proceedings. The same rule applies to Members of the Lords.
The first few sitting weeks of a new Parliament also sees the formation of the new parliamentary select committees, responsible for scrutinising the work of the various government departments, and the election of the Chairs of those Committees. There will also be a Private Member's Bill ballot for MPs which is held on the second sitting Thursday of each session of Parliament. This will therefore take place in January. Private Members' bills in the Lords are usually introduced through a ballot held on the day after State Opening. Given the proximity of Christmas, Parliament will not be fully functional until the New Year.
Lastly, we expect the Government's first budget to be delivered within the first hundred days of the new Government but after the delivery of Brexit on 31 January. Current best guess is the first half of February. Under the Fixed-term Parliament Act 2011 the current Parliament is due to run until 2024.