LISBON, Oct 13 (Reuters) - Portugal's far-right Chega

party fell back to earth in municipal elections, with a far

worse result than it had anticipated after a surge in May that

made it the country's official opposition.

The party won three out of 308 elected mayorships in

Sunday's election, despite having predicted it could win 30. Its

vote share fell to 12%, a far cry from its nearly 23% in the

parliamentary election five months ago.

The ruling centre-right Social Democratic Party (PSD) won

the largest share of mayors' races with 136 including those in

the largest cities Lisbon and Porto, improving from 114 four

years ago. Its centre-left Socialist rivals won 128.

Chega's result still gave it the third most votes of any

party, but it emerged with fewer mayorships than independent

candidates, with 20, and the Communist Party, with 12.

Chega's rise since the election of the group's first member

of parliament in 2019 has shaken up Portugal's political

landscape. It has aligned its rhetoric with Marine le Pen's

National Rally in France and Germany's AfD.

It seeks to clean up the political system, end "gender

ideology" in schools, curb immigration and reduce spending on

housing for Roma communities, a policy it says increases crime.

Ventura acknowledged that his party fell short of

expectations and said that coming to power in Portugal required

having a wide base of elected officials at the local level.

"Today we took a first step in that direction, but we are

still far from that goal," he told reporters.

Political scientist Jose Tomaz Castello Branco of Lisbon's

Catholic University said Chega still needs to demonstrate it

could be "a strong enough local party and not a one-man show" of

Ventura.

He said that despite winning few mayorships, Chega could

still gain institutional legitimacy at the local level by

pushing the PSD to breach "red lines" against cooperating with

the far right in municipalities where it lacks full control.