From the blog "IG Product Updates"

I just wanted to update all Community members to let them know that we have recently reduced the minimum bet sizes on some key indices, commodities, and FX markets. This has been done for both UK spread betting accounts and European CFD accounts.  What are the minimum bet sizes for indices, commodities and FX on IG? Correct as of 6th September 2018 but subject to change   Continued feedback A key aim of Community is to keep a two way dialogue open between our client base