Celtic rock band the Dropkick Murphys do not like Wisconsin Gov. Scott Walker. In fact, they "hate him" and want him to stop using their songs as his opening music.

On Saturday, Gov. Walker was at the Iowa Freedom Summit and used "I'm Shipping Up to Boston" as his intro music, Milwaukee Sentinel reports.

The Dropkick Murphys were not happy, and responded on Twitter.

"Please stop using our music in any way ... we literally hate you !!! Love, Dropkick Murphys," the band reportedly wrote in a tweet Saturday that has since been deleted.

It does not look like the Dropkick Murphys will sue or look for a lawyer in this matter, but they sure are not happy, Bloomberg reports.

"This isn't a legal issue to us-we're not looking to sue someone," lead singer Ken Casey said. "Yes, our words were a little harsh, but it was borne out of frustration with past history of Wisconsin Republicans, such as Jeff Fitzgerald, using our music."

Dropkick Murphys have been an opponent of Walker for quite some time. In 2011, they released a pro-union song titled "Take 'Em Downm" which attacked Walker's state budget plan. The band even created a "Take 'Em Down" t-shirt and directed some of the proceeds to the Workers' Rights Emergency Response Fund.

In 2012, the band wrote this on their Facebook page regarding unions and collective bargaining:

"[We] stand beside our Union and Labor brothers and sisters and their families in Wisconsin and all over the U.S."

Walker, who is in his second term as Wisconsin's Governor, came under harsh criticism in 2011 after introducing a new state budget. In the budget, collective bargaining was limited for most public employees. This led to state-wide protests as well as protesters sleeping and refusing to leave the Wisconsin State Capitol.

Singers have complained about politicians using their music in the past. Tom Petty, the band Survivor and John Mellencamp have all asked for politicians to stop using their songs in their campaigns.