Attendance at the opening prayer in the House of Commons has been voluntary for a long time; the practice is described as non-compulsory, with MPs able to choose whether to attend or wait outside and still keep their seat. The sources I found trace parliamentary prayers back to 1558, but they do not give a single “start date” for when attendance first became voluntary.

What is clear

  • Parliamentary prayers in the Commons date back to 1558.
  • MPs are not required to attend; they can opt out without losing their place for that day’s business.
  • A 2025 report still describes the prayers as a choice for MPs rather than an obligation.

Best answer

So, the safest answer is: attendance was voluntary by at least the modern era described in the sources, and it is currently voluntary. The materials available here do not identify the exact historical year when the change happened.

Short version

If you need a one-line answer for a post: attendance at opening prayers in the British Parliament is voluntary now, and the sources I found don’t pin down the exact year it became voluntary.