The confidence and supply deal shows how Labour could get into power if it needed to form a minority government after a future election.
With the election less than a week away how many seats does Ed Miliband need to get into Downing Street with the help of the SNP?
With a hung parliament almost guaranteed in May, a Conservative Home poll looked at coalition prospects. The Lib Dems and DUP came out on top.
YouGov’s latest poll suggests that most Labour voters think that Miliband should not rule out an SNP deal.