Mexico's Calderon says drug gangs threatening democracy
Organised crime poses an "open threat" to democracy in Mexico, President Felipe Calderon has warned.
Mr Calderon said attempts by drug gangs to manipulate elections was a "new and worrying fact".
Speaking as his sixth and final year in office began, Mr Calderon also defended his decision to use troops to tackle the cartels.
Mr Calderon's speech comes as political campaigns are intensifying ahead of next July's presidential poll.
President Calderon used his speech on Sunday to reiterate his commitment to fight Mexico's drug gangs.
Crime represented a threat to the viability of the Mexican state and national democracy, Mr Calderon said.
"The glaring interference of criminals in the electoral process is a new and worrying development. No political party should remain silent about it," he said.
"It's a threat that affects everyone and we must all, without hesitation, move to stop it."
Mr Calderon's sister last month lost the election for governor in their home state of Michoacan, where local polls were also held.
Reports at the time spoke of gunmen intimidating voters and candidates.
President Calderon, who is constitutionally barred from seeking a second term, has seen his time in office marked by drug-related violence.
More than 40,000 people have died since he deployed troops to take on the gangs.
Mr Calderon defended his strategy and said that 21 of the country's most wanted 37 criminals had been arrested or killed.
He insisted that he would continue work to root out corruption in the police and judicial institutions.
President Calderon will be in office until December 2012 but his successor will be chosen in July.
How the candidates propose to tackle the cartels and improve security are likely to be key questions during the campaign, correspondents say.