According to SCT the project will be tendered as a turnkey contract with the winning bidder being responsible for maintaining the line.

In an effort to ensure transparency and legality in the competition, SCT has appointed an engineer, Mr Humberto Diaz Santillana, as a "social witness" to oversee the bidding process.

A parliamentary inquiry was launched last month to investigate the tendering and subsequent cancellation of the initial contract, which was awarded to a consortium of Chinese and Mexican companies.

Prior to the cancellation of the contract the government had intended to commission the line by 2018, but it is unclear how the inquiry and retendering will affect timescales for construction.

Nonetheless, SCT has confirmed that the government intends to extend the line beyond Queretaro in the longer term to serve Bajío and Guadalajara.