Tickets to Parliament - mostly sold out the minute dates are posted

Edit - I probably misunderstood your question. Were you looking for guided tour or audio self-tour tickets for Parliament? Still confused as the website show open dates when I check. https://www.parliament.uk/visiting/visiting-and-tours/

My original answer below indicates how to attend a Parliamentary Debate - a worthwhile venture. I'll leave it up although I now think this isn't your question. Perhaps someone will be interested or unaware of the option.

I have done this - no ticket required when I attended a Parliamentary Debate. This website indicates Prime Minister Questions is a different story. Applicable "cut and paste below".
https://www.parliament.uk/visiting/visiting-and-tours/watch-committees-and-debates/debates/

"UK residents and overseas visitors are welcome to watch debates in both Houses from the public galleries. Watching debates in Parliament is free of charge for all visitors.

The galleries are open to the public from Monday to Thursday (and some Fridays). Times differ throughout the week and for each House."

"Tickets are not required for general debates. Tickets are required for Prime Minister's Questions and you can request tickets in advance for Ministerial Question Time.

On most days you can just turn up and wait for entry to either Chamber on the day. There is usually a queue for the public galleries, and the Visitor Assistants will be able to inform you of how long your wait is likely to be.

Visitors wishing to watch debates should enter via the Cromwell Green entrance."

Re: Prime Minister Question:
"Tickets are free of charge and are available only to UK residents, who should contact their Member of Parliament or a Member of the House of Lords."

https://www.parliament.uk/visiting/visiting-and-tours/watch-committees-and-debates/prime-ministers-questions/

Thanks so much, ORDtraveler. Yes, I'm looking for a good live-guided tour. Sitting in on a Questions Time would be fantastic, as well!

I'm seeing availability in February and March Saturdays. There are limited tour times - perhaps your dates coincide with an unavailable period, not simply "sold out".

From https://tickets.parliament.uk/timeslot/uk-parliament-english-guided-tour :

"When the tours run
• Saturdays throughout the year.
• During recess, tours run from Tuesdays to Saturdays.
• Last admission 16:00."

Good luck!

Yes, but you'll notice that March 8, for instance, has a total availability of 1 ticket each in 5 timeslots. The remaining 21 slots are booked out. Same with every other date that shows any availability. I'm thinking there's a secret to getting 2 tix before they're snapped up.

I wonder if there’s something going on during March that means they’re not doing guided tours? Or if they just haven’t loaded the availability correctly.

It absolutely isn’t the kind of tourist attraction that sells out like crazy - nothing like Anne Frank House or Big Ben or Ceremony of the Keys.

Keep an eye on it and see if it changes nearer the time. February has loads of availability and March isn’t significantly busier than Feb. So either they’re not offering many guided tours in March or they just haven’t loaded all the tickets yet, is my thinking.

Or do a self-guided tour? There’s loads of availability in March.

“ Is there a trick to this, like with the Ann Frank house (log on Tues 1:00 am Pacific time/9:00 am Amsterdam time, when the next week's worth of tix goes on sale)?”

Not exactly relevant to your question, but just to avoid confusion; tickets to the Anne Frank house go on sale at 10 am Amsterdam time, not 9 am. And the tickets that go on sale are for the week that starts 6 weeks later.

Thanks, everyone. I'll take a deep breath and keep checking in at Parliament.uk in advance of my trip. And thanks for the Anne Frank house time correction, DutchTraveler. The Anne Frank House anchors a number of resistance-themed museums in Amsterdam that impacted us profoundly.