The Brexit deadlock has contributed to the longest session of Parliament since the English Civil War.
Tuesday will mark the 300th sitting day of a session which has stretched over three different years, starting on June 13, 2017.
But the current session is unlikely to break the record of the Long Parliament, which lasted for 3,322 days between 1640 and 1653.
A new parliamentary session would be marked by a Queen's Speech setting out the government's agenda, but the need to deal with Brexit and Theresa May's fragile hold on power has contributed to the monarch's absence from the Palace of Westminster.
Downing Street today defended the approach, with the Prime Minister's official spokesman telling reporters that Mrs May and the Government "decided upon an extended session in order to pass the legislation to deliver Brexit".
"That work remains vital and, obviously, ongoing."
Analysis by the House of Commons Library read: "What makes the 2017-19 session unusual is that it has lasted for more than three years.
"This has been to permit the passage of Brexit-related legislation. This parliamentary session has now overtaken the 296 sitting days in the 2010-12 session, which was previously the longest since the Civil War.
"It has therefore also become the longest session since the union of England and Scotland in 1707."
Divisions over Europe contributed to the 240-day session of 1992-93, characterised by bitter debates over the Maastricht Treaty.
The 1997-98 session, with 241 days, saw the passing of legislation creating devolved institutions in Scotland and Wales.
Additional reporting by Press Association.
