By its calculations, Frontier Airlines says it doesn’t have enough votes among Spirit Airlines shareholders to win the vote for a proposed merger between the two domestic carriers.The revelation came in a letter made public on Monday from Frontier CEO Barry Biffle, who asked his counterpart at Spirit, CEP Ted Christie, to again delay a stockholder vote scheduled for Friday, July 15, in order to continue lobbying for votes.ADVERTISINGIf Spirit complies, it would be the fourth adjournment of a shareholder vote in the last five weeks. Trending Now Frontier had already informed Spirit on Monday that it would no longer be raising its bid, as it has done since April going toe-to-toe with JetBlue Airways, the other suitor looking to take over Spirit. Biffle said Frontier’s latest bid would be its last and final offer for Spirit.“…We still remain very far from obtaining approval from Spirit stockholders based on the proxy data we received as of July 8,” Biffle wrote to Christie and General Counsel Thomas Canfield.Frontier has Christie’s support. Frontier’s had Spirit’s Board of Directors' support. What it doesn’t have, however, is the backing of the ultimate arbiters in the stockholders. TravelPulse recently wrote that it’s clear that what Christie and the Board want are vastly different from what the stockholders want – a lucrative payday.Frontier’s offer is worth about $4.13 a share to Spirit stockholders with a deal for almost 1.9 shares of Frontier stock for every share of Spirit. That’s about $1 billion less than JetBlue’s proposal of $33.50 or a $3.7 billion total package.For the latest travel news, updates and deals, subscribe to the daily TravelPulse newsletter. Adblock test (Why?)