Spanish Prime Minister Mariano Rajoy has spent much of the political capital he won seven months ago in the biggest landslide in 30 years, floundering against a crisis that risks making Spain the first $1 trillion economy to need a sovereign bailout, investors and analysts say.

Rajoy, singled out by leaders at the Group of 20 summit, has been taunted by opposition lawmakers and commentators as borrowing costs soared to a euro-era record even after Spain's banks received a 100 billion-euro ($127 billion) lifeline. Rajoy called the rescue a victory that solved lenders' problems.

“He clearly doesn't get it,” said Gary Jenkins, founder of Swordfish Research Ltd. near London, who has tracked bond markets for more than 15 years. “Spain needs someone who can come in and grasp the seriousness of the situation and react to that, not just pretend everything's okay.”