This was likely due to the Christian Democrats' opposition from within the four-party centre-right governing coalition despite their being the only party opposing the move.
As Prime Minister from 1965 to 1971, he headed a four-party center-right coalition.
Almost all politicians thought Giuliano Amato's scandal-battered four-party coalition had to be replaced by a broader-based one.
This week, in two days of voting, Italians have come within a whisker of denying a majority to their governing four-party coalition.
The Socialist Prime Minister heads a fragile, four-party coalition that took office in June after months of political wrangling.
He became prime minister of Bavaria for a second time in 1954, when he led a four-party coalition of conservative and liberal parties until 1957.
Slovakia's four-party coalition holds on a narrow 79-71 majority in the 150-seat parliament, and is thus vulnerable to dissent from backbenchers when introducing legislation.
The election left the governing four-party coalition with only 48.8 percent of the votes, too low to build a new governing alliance.
Some of Mr. Cardoso's problems may stem from the difficulty of holding together a fractious four-party coalition with no common ideology.
The four-party coalition has pledged to improve Slovakia's ties with neighbouring Hungary.