Uber's war against New York City Mayor Bill de Blasio escalated today with a large masthead ad on The New York Times' homepage calling out the politician's proposal to limit the number of city licenses available for drivers.

The ad's copy references a Times opinion piece last week about why de Blasio's legislation is "a bad idea." Another Uber ad on The New York Times' website today claims that the mayor's proposed idea is more about politics than policy.

Both ads on NYTimes.com link to Uber's online petition where people can learn about the company's issues with NYC regulation and sign up for an email list.

Interestingly, the ad is also running on NYDailyNews.com with the same copy citing The New York Times' editorial.

The mayor's office is concerned that Uber's rapid growth has increased congestion in Manhattan and slowed travel times. According to the city's Department of Transportation, the number of for-hire vehicles operating in New York City has increased 63 percent since 2011, with three-quarters of rides in these new vehicles originating in Manhattan south of 60th Street. De Blasio has proposed a one-year freeze on new Uber licenses until the traffic impact can be analyzed.

As the largest ride-sharing startup, Uber's been in a full marketing blitz against de Blasio recently. Last week, Uber ran a campaign in its app urging riders to sign the petition. It's also been using email marketing, running cable TV ads and playing up supportive stories on Twitter.

We've reached out to Uber for comment on today's high-profile ad push and will update if we hear back.

Check out Uber's NYC television spot below: