Mexico City ? Supporters of leftist candidate Andres Manuel Lopez Obrador briefly took over highway toll booths Tuesday, giving thousands of motorists free passage to the capital as they escalated their demands for a full recount in July’s close election.

A day before electoral officials were to begin a partial recount, Lopez Obrador’s die-hard backers were becoming more radicalized and said they were ready for a protracted fight.

But the fiery former Mexico City mayor who ran his campaign on improving the lot of millions of poor has lost supporters who were turned off by his blockade of the city center.

Some fear that while Lopez Obrador has urged his followers to remain peaceful, he may not be able to prevent demonstrations from erupting in violence.

The seizure of the toll booths prompted President Vicente Fox’s spokesman, Ruben Aguilar, to threaten for the first time the use of force. But demonstrators backed off before that could happen, abandoning the booths shortly after the end of morning rush hour.

An official in Lopez Obrador’s party said the seizure of toll booths was the start of a week of new protests across the nation.