5 years written references + partner's passport?

I'm in the process of accepting a job offer through a recruitment agency, but they are now asking for 5 years of written references, with no gaps >4 weeks.  They also are saying they require my partner's passport and a copy of our marriage certificate. 

(I've already provided my passport and BRP, a copy of both my BS and MRes degrees, and NI Number)

Has anyone needed to do this before?  To me it sounds a bit extreme and slightly ridiculous....

Seems ridiculous to me.

I would push back.  Why in the world would they need your partners details?

I'm in the process of accepting a job offer through a recruitment agency, but they are now asking for 5 years of written references, with no gaps >4 weeks.  They also are saying they require my partner's passport and a copy of our marriage certificate. 

(I've already provided my passport and BRP, a copy of both my BS and MRes degrees, and NI Number)

Has anyone needed to do this before?  To me it sounds a bit extreme and slightly ridiculous....

I've been asked for all of those things before, I also thought it was extreme and ridiculous.  I was only asked for a copy of my partner's passport when I was still on FLR(M).  I was asked for a marriage certificate copy because I still had my maiden name on my passport.

When I applied for my current job I had to supply references from all my jobs/universities for the last 5 years and I had no choice about them being contacted... all of them were.

However, I was applying for a job with a UK government agency and the post required full UK government security clearance, so I also had to fill provide lots of information (including all my addresses for the last 5 years), and fill out detailed security questionnaires about family members and current/previous partners.

So, I guess it might depend on what kind of job it's for, but it does seem a bit extreme/ridiculous for them to request your partner's passport and your marriage certificate.

Thanks everyone for confirming what I was thinking.

ksand- it's nothing requiring any sort of UK security clearance like your role; it's developing and analysing on new toothpaste formulations..

I will comply to an extent, but I will point out that their expectations are a bit high, and there will obviously be some gaps since I moved countries less than 5 years ago. 

I'll let you know how it goes. I'm just annoyed because I expected to have had everything sorted before I left for Christmas (which is in about 12 hours)...

When I accepted my job I had to provide details from the last 3 years of where I lived and worked. This was part of the animal rights vetting procedure since they do animal research where I work. They have to make sure they don't employ anyone who has a history of animal rights activism since it might jeopardize the work. Perhaps this is something similar? You should be able to ask why they require this information and what they use it for. I don't recall having to give any of my spouse's details, though.