Spain's acting premier says he believes no government will be formed following an inconclusive December election and that Spaniards will probably cast ballots again in June.

Prime Minister Mariano Rajoy made the prediction in Brussels to British Prime Minister David Cameron during a break from a summit about Britain's renegotiation of its ties with the European Union.

Rajoy said in the comments Thursday captured on video that Spain's most likely political scenario is a fresh election on June 26.

Rajoy's Popular Party won the most votes on Dec. 20 but fell far short of regaining its parliamentary majority. The election saw strong showings for two upstart parties, upending Spain's traditional two-party system.

The conservative Rajoy failed to cobble together a government. Socialist leader Pedro Sanchez is now trying.