Spain was willing to declare war against neighbouring Portugal in the last year of General Francisco Franco`s right-wing dictatorship, in the name of the fight against communism, a newspaper reported Monday.

Franco`s last prime minister, Carlos Arias Navarro, adopted this position during a March 1975 meeting in Jerusalem with then US deputy secretary of state Robert Ingersoll, El Pais reported, citing documents from US national archives.

The meeting was held at a time when communism was gaining ground in Portugal in the wake of a near bloodless military coup in April 1974 that toppled a right-wing dictatorship that had ruled the country for nearly five decades.

`Spain would be willing to lead the anti-communist fight (in Portugal) alone if necessary,` Ingersoll wrote in a diplomatic cable he sent to then secretary of state Henry Kissinger, the paper said.

`Portugal is a serious threat to Spain, not only because of the development of the (internal) situation, but also because of the external support which it could obtain and which would be hostile to Spain,` added the cable, which the newspaper said it had access to.

Navarro was `deeply worried` by events in Portugal and sought a guarantee that Washington would support Spain if a war were to break out between the two countries, Ingersoll wrote according to the newspaper.

`It is a strong and prosperous country. It does not want to ask for help. But it trusts that it would have the cooperation and understanding of its friends, not only in the interest of Spain but also in the interests of all those who think the same way,` he wrote.

Portugal was an ally against communism under right-wing dictator Antonio de Oliveira Salazar, who supported Franco during Spain`s 1936-39 civil war.

Salazar was succeeded by Marcelo Caetano in 1968. He died in 1970, five years before his ally Franco.