Hmmm it is a bit odd if you have been here 20 years, and are a permanent resident.
Have you asked them why?
Me and DH went away with a couple 2 years ago with a couple - DH he works with him - she is French and been here 10 years by then, (working here, and no plans to go back,) and they are not married, and we all stayed at a travelodge. No-one asked for her passport.
So I am a bit baffled.
And ignore ana, (on page 1) you have said nothing 'racist!' 
And ignore the baiters saying 'go stay somewhere else then!' And 'grow up!'
YANBU and I would be asking them (very loudly) 'WHY do you need my passport details when I am a UK resident?'
If they can't give a good answer, use someone else anyway and slag them off all over twitter for being arseholes.
Oh and travelodge do NOT ask for photo I.D. unless you are paying by cash/paying when you get there. And as the VAST majority of people book in advance, they will not be asked.. So anyone saying that is chatting shit.
Could this be the case for you @DorothyL? Did you turn up and pay cash (and not pre-book?)