You stand up before your colleagues, clear your throat and prepare to speak. Through the night. Non-stop.
Perhaps you've brought a packed lunch. You might have some phone books to read aloud, too, in case you run out of things to say.
And you've no doubt thought very carefully about what to do when you need to visit the toilet.
Filibustering - a delaying tactic in a parliament, typically whereby lawmakers drag out speeches to the end of the allocated time, so that no vote can be held - is one of the oddest quirks of democratic politics the world over.
"It's a kind of urological mystery as to how he was able to do it”
Biographer, Strom Thurmond
Distinguished elected representatives have been seen engaging in truly epic feats of time-wasting in an effort to slow down or block legislation.
The most spectacular examples have come from the US Senate, where in 1935 Louisiana Democrat Huey Long tried to scupper a bill by rambling for more than 15 hours, reciting recipes for Roquefort salad dressing and discussing in detail the best way to fry oysters.
Twenty-two years later, the veteran South Carolina Senator Strom Thurmond, set a record by filibustering a civil rights bill for 24 hours and 18 minutes, reading aloud the voting laws of each US state and quoting George Washington's farewell address in its entirety.
The filibuster - derived from the Dutch word "vrijbuiter", meaning "pirate" - is so integral to the US political system that Frank Capra's 1939 movie Mr Smith Goes to Washington features James Stewart's hero delivering a lengthy filibuster in the Senate in which he saves the day by exposing political corruption.
In recent years, members of the US senate have been able to "silently filibuster" - it has been enough to simply signal an intention to block legislation as long as the backers of the bill cannot muster a three-fifths majority.
But Harry Reid - the Democratic majority leader who himself held the floor for nearly nine hours in 2003 - now wants anyone with an objection to stand up and voice their opposition to a bill if they want to stand in its way.
Famous US filibusters
- The longest filibuster in history came when US Senator Strom Thurmond spoke from 20:54 on August 28 1957 until 21:12 the following evening against civil rights reforms
- US Senator Alfonse D'Amato (above, left) of New York kept going for 23 hours and 30 minutes in an attempt to block a military bill in 1986
- Robert Byrd (right) of West Virginia spoke against the 1964 Civil Rights Act for 14 hours 13 minutes.
- Huey Long (center) of Louisiana discussed the merits of various recipes during his 15-hour filibuster in 1935
It could mean a return to the debates of the 1950s and 1960s, when southern politicians like Strom Thurmond and Robert Byrd spoke through the night in an effort to block civil rights reforms.
If so, a new generation of lawmakers may have to summon hitherto untapped reserves of physical endurance - though they may not welcome the comparison with Thurmond, whose record-breaking filibuster was an attempt to block the extension of voting rights to African Americans.
According to Thurmond's biographer Joseph Crespino, a history professor at Emory University, the segregationist politician - who died in office in 2003 aged 100 - was extremely fit and prepared meticulously beforehand.
Thurmond brought with him supplies - including a hunk of pumpernickel bread, sirloin steak, lozenges, fruit juices and water, Crespino says. The senator spoke in a quiet monotone to preserve his voice.
Apart from a half-hour break in the early hours when the rules permitted him to give way to fellow Senator Barry Goldwater, Thurmond stood on the floor of the chamber throughout.
For historians, the most puzzling aspect of the feat is how exactly he managed to avoid visiting the bathroom for so long.
"It's a kind of urological mystery as to how he was able to do it," says Crespino.
"Afterwards, one of the first questions reporters asked him was how he was able to hold his bladder."
Thurmond told them he had visited the Senate steam room beforehand to dehydrate himself, so his body would absorb liquids "like a sponge", Crespino adds.
But rumors persisted suggesting he had employed a more furtive method. An African American Capitol employee named Bertie Bowman claimed in his memoirs that the senator had, in fact, been fitted with a catheter tube.
Filibustering around the world...
- In December 2010 Austrian Green MP Werner Kogler made a speech lasting 12 hours and 42 minutes
- Canadian Conservative MP Tom Lukiwski talked for six hours during a parliamentary committee in 2008
- In the UK in February 1983, Labour's John Golding spoke for 11 hours on the Telecommunications Bill - but as this was at a standing committee and not in the Commons chamber, he was able to take breaks
In 1936 the Independent Unionist MP Tommy Henderson spoke for almost 10 hours straight in the Parliament of Northern Ireland
While the US may have set the standard for filibustering during the 20th Century, the practice has a long history around the world.
In ancient Rome, Cato the Younger would frustrate Senate legislation he opposed by speaking until nightfall, by which time business had to be concluded.
The longest speech in House of Commons history - a six-hour marathon by Henry Brougham in 1828 - was not, in fact, a filibuster. However, Charles Stewart Parnell's Irish Parliamentary Party regularly used the tactic at Westminster during the 1880s in an effort to get home rule onto the parliamentary agenda.
The longest 20th Century House of Commons speech was made by Conservative MP Sir Ivan Lawrence, who spoke for four hours 23 minutes against the Fluoridation Bill in 1985.
Sir Ivan, a barrister, was an experienced enough public speaker to keep extemporizing on the topic, although his efforts were not enough to prevent the motion becoming law.
"I don't think I even had any water with me," he recalls. "It was the adrenaline that kept me going.
"Unfortunately, everyone thought this was a great wheeze.
"There were various people interrupting me - 'Is my right honorable friend aware that he's promised me a lift home tonight?' and so on."
In the great civil rights filibusters you couldn't see all this stuff on the TV”
Gregory J Wawro
A friend later told Sir Ivan he kept Hansard's transcript of the debate by his bed to help him get to sleep at night.
Procedural changes have now made it very difficult to filibuster government-backed legislation at Westminster, although Labour peers were accused of attempting it during the AV referendum debate.
Occasionally backbenchers' bills or motions are talked out. In 2005 Labour MP Andrew Dismore spoke for 197 minutes against a private members bill to clarify the degree of force a householder can use against intruders.
Not all filibusters require long speeches. New Zealand MPs filibustered local government reforms in 2009 by proposing thousands of amendments - many of them in the Maori language, which then had to be translated into English.
However, many legislatures - including both houses of the Australian parliament and the US's own lower chamber, the House of Representatives - have strict rules on how long representatives can speak for.
The US Senate does not, though 60 of the 100 senators can vote for cloture - that is, to bring the debate to a vote.
Increased partisanship has been blamed for a surge in the number of silent filibusters. But if Reid's plans to change the rules go through, marathon speeches could make a comeback to the chamber.
Whether public opinion will tolerate them, however, is another matter.
In an age of 24-hour news, politicians may be more reluctant to engage in baroque displays of time-wasting than their predecessors, argues Gregory J Wawro, professor of politics at Cornell University, and co-author of Filibuster: Obstruction and Lawmaking in the United States Senate.
"In the great civil rights filibusters and the days of Huey Long, you couldn't see all this stuff on the TV," Wawro says.
"Whether senators would want to be seen reading from the phone book or cookbooks remains to be seen."
As well as stocking up on snacks, they would have to think about what their constituents thought of their ostentatious time-wasting. It's enough to make even the most loquacious mouth go dry.