MEXICO CITY (Reuters) - Leftist Andres Manuel Lopez Obrador, the favorite to win Mexico’s July 1 presidential election, has asked prominent businessman Alfonso Romo to be his chief of staff, the candidate’s campaign said late on Friday.

Businessman Alfonso Romo gestures during an interview with Reuters in Monterrey, Mexico February 21, 2017. Picture taken February 21, 2017. REUTERS/Daniel Becerril

Lopez Obrador’s team made the announcement in a statement as the election campaign draws to a close. Romo, a tycoon with a business empire based in the northern state of Nuevo Leon, has been a top economic adviser to Lopez Obrador for several years.

Opinion polls give the former Mexico City mayor a commanding lead in the race to become the next president, with some showing he has twice the support of his nearest rival.

Romo, a two-time Olympic showjumper who runs a major brokerage, has backed the energy reform at the heart of the current government’s economic agenda, in spite of opposition to it from many of Lopez Obrador’s supporters on the left.

Outgoing President Enrique Pena Nieto, who is barred constitutionally from seeking re-election, pushed through legislation in 2013-14 that opened up Mexico’s long-shuttered oil and gas industry to more private and foreign investment.

Lopez Obrador, a longstanding opponent of the reform, has said he wants to review the contracts awarded under the liberalization for any signs of corruption, and he could freeze further auctions of oil and gas blocks in Mexico.

Romo said in April, however, the reform would not be reversed.

The government says billions of dollars worth of contracts have been awarded under the energy reform to oil majors including Exxon Mobil and Royal Dutch Shell.

Representatives for Lopez Obrador and Romo did not immediately say if Romo had accepted the invitation.

Mexico’s next president is scheduled to take office on Dec. 1 after a five-month transition period.