CAMBRIDGE, ENGLAND - APRIL 27:  Cockapoo dog 'Bonnie' is seen amongst Liberal Democrats supporters as party leader Tim Farron campaigns for the British general election at Eastfield regeneration site on April 27, 2017 in Cambridge, England. Mr Farron has been campaigning in the Cambridgshire area alongside parliamentary candidate and former MP Julian Huppert, Mayoral candidate Rod Cantrill and cadidate for South Cambridgeshire Susan Van De Ven.  (Photo by Chris J Ratcliffe/Getty Images)
CAMBRIDGE, ENGLAND - APRIL 27:  Cockapoo dog 'Bonnie' is seen next to a European Union flag and Liberal Democrats supporters as party leader Tim Farron campaigns for the British general election at Eastfield regeneration site on April 27, 2017 in Cambridge, England. Mr Farron has been campaigning in the Cambridgshire area alongside parliamentary candidate and former MP Julian Huppert, Mayoral candidate Rod Cantrill and cadidate for South Cambridgeshire Susan Van De Ven.  (Photo by Chris J Ratcliffe/Getty Images)
CAMBRIDGE, ENGLAND - APRIL 27:  Liberal Democrats party leader Tim Farron walks over to pet cockapoo dog 'Bonnie' as he is campaigning for the British general election at Eastfield regeneration site on April 27, 2017 in Cambridge, England. Mr Farron has been campaigning in the Cambridgshire area alongside parliamentary candidate and former MP Julian Huppert, Mayoral candidate Rod Cantrill and cadidate for South Cambridgeshire Susan Van De Ven.  (Photo by Chris J Ratcliffe/Getty Images)
CAMBRIDGE, ENGLAND - APRIL 27:  Liberal Democrats leader Tim Farron pets cockapoo dog 'Bonnie' whilst campaigning for the British general election at Eastfield regeneration site on April 27, 2017 in Cambridge, England. Mr Farron has been campaigning in the Cambridgshire area alongside parliamentary candidate and former MP Julian Huppert, Mayoral candidate Rod Cantrill and cadidate for South Cambridgeshire Susan Van De Ven.  (Photo by Chris J Ratcliffe/Getty Images)
CAMBRIDGE, ENGLAND - APRIL 27:  Cockapoo dog 'Bonnie' is seen next to a European Union flag and Liberal Democrats supporters as party leader Tim Farron campaigns for the British general election at Eastfield regeneration site on April 27, 2017 in Cambridge, England. Mr Farron has been campaigning in the Cambridgshire area alongside parliamentary candidate and former MP Julian Huppert, Mayoral candidate Rod Cantrill and cadidate for South Cambridgeshire Susan Van De Ven.  (Photo by Chris J Ratcliffe/Getty Images)