Bennion was born in Tamworth, Staffordshire and educated at Queen Elizabeth Grammar School.

Bennion advised Charles Kennedy on agricultural issues during his leadership of the Liberal Democrats.

When Liz Lynne stepped down in February 2012, electoral rules meant that Bennion, as the next Liberal Democrat candidate on the list, took her seat.

Bennion stood as the Parliamentary candidate for Lichfield in 1997 and 2001, for Tamworth in 2005, Telford in 2010 and Birmingham Hodge Hill in 2015 and 2017.

Anthea McIntyre became an MEP in November 2011 when the relevant provisions of the Treaty of Lisbon came into effect, her addition being based on the 2009 vote.