For folks in the United Kingdom, Vanguard index funds are now accessible through their new website[0]. Their website was released mid May 2017 and has caused a good shakeup[1] in the individual investor space as other stock brokers commission charges are incredibly high.
[0] https://www.vanguardinvestor.co.uk/home
[1] http://www.scotsman.com/business/markets-economy/bill-jamies...
They have mentioned that Vanguard will be looking to give access to Europe in 2018.
[Edit] - Removed Financial Times link as they have a paywall.