© Licensed to London News Pictures . 22/06/2016 . Birmingham , UK . CAROLINE LUCAS and PADDY ASHDOWN . British Conservative Party Prime Minister David Cameron , Tim Farron and Paddy Ashdown from the Liberal Democrat Party and Harriet Harman from the Labour Party , attend a joint rally at Birmingham University in support of the REMAIN in EU campaign , ahead of referendum polling opening tomorrow morning (23rd June 2016) . Photo credit: Joel Goodman/LNP