The city and Albany need to boost financial support to the MTA otherwise straphangers could face higher fares and less service in a doomsday scenario, a report released by the state comptroller's office Tuesday warned.

State Comptroller Tom DiNapoli said the MTA's 2015-19 capital plan, which funds big projects like the Second Avenue Subway, has a $9.8 billion funding gap despite a strong economy and record ridership.

The MTA has requested that both the city and state increase its funding to the capital plan to close the comptroller agreed this was the best solution.

"If the MTA doesn't get the funding it needs, the MTA will have to choose between cutting the size of the capital program or borrowing more, which could lead to less reliable service or higher fares and tolls," DiNapoli said in a statement.

The report said the MTA plans to balance operating budgets through 2017, however, there will be a budget gap of $175 million in 2018 and a $224 million the following year.

Labor agreements will expire next year and the future costs of those contracts are up in the air, according to the report. If the economy worsens in the next few years, the agency will also have to deal with lower revenues, DiNapoli warned.

The agency plans on 4% hikes to fares and tolls in 2017 and 2019 but they could rise higher depending on how the capital budget is funded. The MTA asked has New York state increase its contribution to the capital program by $7.3 billion to a total $8.3 billion and New York City increase its contribution by $2.5 billion to $3.2 billion.

The funding quagmire created a war of words between Gov. Andrew Cuomo and Mayor Bill de Blasio who have accused each other of not paying their fair share for the capital funding.

Even though Cuomo pledged to give the MTA $8.3 billion, De Blasio's office said the state has underfunded the MTA for years.

"New York City has funded three-quarters of the MTA's operating budget and put in more than twice as much capital funds as the State. The State must do its job and work with the City on a fair and responsible framework to move forward," de Blasio spokeswoman Amy Spitalnick said in a statement.

Cuomo's office didn't return messages for comment on DiNapoli's report, however the MTA and Transit Workers Union also criticized the city. MTA spokesman Kevin Ortiz said the report demonstrates why the city needs to contribute more than $657 million.

"Facts are facts, and the facts in this report make clear it is long past time for the city to contribute its fair share to the MTA Capital Program," he said in a statement.

TWU Local 100 President John Samuelsen, who has been running newspaper ads bashing the mayor, warned de Blasio that he would be "abandoning" the city's working families if he didn't contribute to better transit service.

"When stations continue to fall apart, trains begin to derail and the Second Ave. subway project grinds to a halt, working New Yorkers will have Mayor de Blasio to blame," he said in a statement.