There's an all-party parliamentary group on the folk arts, made up of a couple of SNP MPs, one Tory MP and one Labour peer.

MSP rather than MP, but John Swinney posted a tribute when Rod Paterson died: "an amazing musician who made a tremendous contribution to traditional music in Scotland".

IIRC Jeremy Corbyn was at the 2015 Barbican concert in memory of Ewan MacColl. Can't think of anything else off the top of my head.