MEXICO CITY (Reuters) -- Mexican President-elect Felipe Calderon, who takes office on Friday, will announce the names of his interior and foreign ministers on Tuesday, a source close to Calderon said.

The source said Calderon, a conservative who narrowly won the July 2 presidential election, will fill a third, less important, Cabinet post.

Calderon's foreign minister will be in charge of international relations, Mexico's northern neighbor.

Hundreds of thousands of Mexicans and other Latin Americans cross illegally into the United States each year in search of work and a better life.

Calderon's interior minister is also a key appointment and will immediately face the task of sorting out persistent protests in the southern state of Oaxaca.

Six months of protests against Oaxaca Gov. Ulises Ruiz, who critics say is corrupt and authoritarian, have left their mark on the state capital, a tourist haven for North Americans and European visitors.

Oaxaca City's hotel industry has nosedived in the protests and graffiti has been daubed on many historic and public buildings.

In October, federal police forced their way into the city to try to end the conflict that has killed more than a dozen people. On Saturday, protesters started fires in four government buildings.

Calderon has already named his economic team. Former senior International Monetary Fund official Agustin Carstens, a Wall Street favorite, will be his finance minister.

Calderon faces a raucous start to his presidency. Leftist opposition deputies have said they will prevent him from swearing in at a traditional ceremony in Congress on Friday in protest at what they say was fraud on election day.

Leftist ex-candidate Andres Manuel Lopez Obrador declared himself "legitimate president" in front of over 100,000 supporters in a square in the capital on Nov. 20, to push his allegations of electoral fraud.

A court ruled those claims invalid and declared Calderon the winner by less than one percentage point. -----Poll finds most Mexicans oppose protest

Most Mexicans disapprove of plans by Mexico's main leftist party to disrupt Friday's swearing-in ceremony of President-elect Calderon, according to a poll released.

The poll, published in the El Universal newspaper, found 64 percent of those surveyed disapproved of a blockade by the leftist Democratic Revolution Party of Obrador while 26 percent favored the protest.

The figure indicated that even many of those who voted for Obrador disapprove of the action. Obrador is protesting official results showing him with 35 percent of the vote on July 2, just behind Calderon.

Lopez Obrador's supporters have vowed to block the inauguration of Calderon but have not specified how they plan to do so.