Mexico opposition to dominate key finance committees

MEXICO CITY, Sept 30 (Reuters) - Mexico's leading opposition party will have the most lawmakers on the budget and finance committees in the lower house of Congress, both key to President Felipe Calderon's push to reform the tax system.

The center-left Institutional Revolutionary Party, or PRI, will chair the budget committee, and it will account 15 of the 34 lawmakers on the finance committee, according to congressional documents published on Wednesday.

The two committees are responsible for drafting any changes to tax laws and finalizing the 2010 budget bill.

Mexico is trying to avoid a possible debt downgrade by credit ratings agencies worried about its paltry tax collection and the government's dependence on oil, which funds more than a third of government spending.

The PRI became the largest party in the lower house of Congress, displacing Calderon's conservative National Action Party, or PAN, after mid-term elections in July.

The PAN is now the second-biggest party in the lower house with 29 percent of seats compared to the PRI's 47 percent. The leftist Democratic Revolution Party, or PRD, is the third biggest block with 14 percent.

PRI deputy Luis Videgaray will head the budget committee and 19 of the 42 members will be from his party, while Mario Becerra from the PAN will lead the finance committee.

The PRI has already rejected the backbone of Calderon's proposal - a controversial 2 percent tax on all sales, including food and medicine currently exempt from other taxes.

The PRI said the sales tax hike would hurt the country's poor in the midst of an economic downturn. But this week PRI leaders suggested that they may be open to approving a sales tax increase if food and medicine remain exempt. (Reporting by Anahi Rama; Editing by Kenneth Barry)