MADRID (Reuters) -Spanish conservative leader Alberto Nunez Feijoo failed on Wednesday to secure enough votes in the lower house to become prime minister.

Feijoo, whose People's Party had won the most seats in an inconclusive election in July, failed to convince enough legislators from other parties to back him to win an absolute majority.

Feijoo received 172 votes in favour with 178 against and no abstentions. Spanish law allows Feijoo a second attempt on Friday, when a simple majority would be enough for him to be elected prime minister.

While Feijoo was given the first stab at forming a government, it is Acting Prime Minister Pedro Sanchez who has a more realistic – albeit difficult – chance of persuading lawmakers in parliament to support him in another term.

Feijoo told reporters after the vote: "It is clear that we have done everything we can, and that Spain can rest assured, because we are going to continue to work for it."

Should Feijoo fail on Friday, Sanchez will need to negotiate with Catalan pro-independence parties, who are demanding a controversial and unpopular amnesty for leaders and activists involved in the 2017 attempt to separate the region from Spain as a condition for their support.

Sanchez would have two months to negotiate an agreement before fresh elections are called if he also fails.

(Reporting by Inti Landauro, Belen Carreno and Emma Pinedo; Writing by Charlie Devereux; Editing by Aislinn Laing, William Maclean)