Lucas first suggested "progressive pacts" to work on a number of issues including combating climate change and for electoral reform, following the results of the 2015 general election. She then reiterated the call alongside Bartley as they announced their plan to share the leadership of the party. Following the vote to leave the European Union in June 2016, Bennett published an open letter, calling for an "anti-Brexit alliance" potentially comprising Labour, the Liberal Democrats and Plaid Cymru to stand in a future snap election in English and Welsh seats. The Green Party stood in 457 seats in the 2017 general election, securing 1.6% of the overall vote, and an average of 2.2% in seats it stood in. While it was a disappointing result after the 2015 success, this was still the second-best Green result in a general election, and Brighton Pavilion remained Green with an increased majority.