Toronto Mayor Rob Ford is leaving the door open to making the construction of the downtown relief subway line the next transit priority for the city.

When asked by a reporter at a news conference Monday morning about whether he would support prioritizing the downtown relief line (DRL), Ford replied: "It's up to [TTC CEO] Andy Byford."

"I'm open up to the idea that benefits the city, that benefits the users of the TTC. I campaigned on subways," he said.

"We're going to get subways — the relief line, the Sheppard line, Eglinton hopefully will go underground. Subways are coming to the city, one way or another."

Ford's comments come amid renewed interest and speculation about the construction of the downtown relief subway line, which is aimed at easing crowding on the Yonge line. Byford has said the line should be the TTC's next priority. TTC Chair Karen Stintz has also championed the DRL.

The TTC on Wednesday will meet to consider a staff report that calls on provincial agency Metrolinx to prioritize the DRL by setting a 15-year target date for its construction, given ridership in the downtown is projected to grow by more than 50 per cent between now and 2031.

Currently, the DRL is only included in Metrolinx's 25-year plan for construction of new transit in the Greater Toronto and Hamilton area. The report estimates the first section of the line, which would run from St. Andrew station on King Street West, along King and then swing north to connect with the Bloor-Danforth line at Pape station, would cost $3.2 billion.

It's not immediately clear how to pay for construction of the new line. Council's executive committee has given the green light for staff to start public consultations on implementing new revenue tools to fund transit expansion in the city and the Greater Toronto Area, although Ford has said he opposes any new taxes or user fees.