Alleged Boston Marathon bomber Dzhokhar Tsarnaev is asking a judge to ease up on his “unnecessarily harsh and isolating” confinement at the Federal Medical Center prison at Fort Devens — with his lawyers complaining he’s lonely and has no TV or radio — according to court papers filed today.

The 20-year-old terror suspect’s taxpayer-funded legal team asks U.S. District Court Judge George O’Toole, Jr., to vacate several “extraordinary and severe” administrative measures imposed on Tsarnaev by federal prosecutors. His lawyers argue the restrictions are unconstitutional and are hindering their efforts to build their defense.

The lawyers claim the restrictions:

• denied them access to Tsarnaev at Devens on at least one occasion in August.

• limit Tsarnaev’s non-legal phone calls and mail to his parents and siblings. He can send just one letter from prison a week, and to adults only.

• prevent him from praying with other inmates.

• forbid him from accepting family photographs.

Tsarnaev, they said, doesn’t even have a television to watch, a radio to listen to or a cellmate to make chitchat with.

“The government has not made any persuasive showing why these restrictions are necessary, nor has it demonstrated that less restrictive alternatives would not suffice,” the filing in U.S. District Court reads. “Mr. Tsarnaev has made no effort to communicate with non-family or media, and is unlikely to do so.”

The attorneys noted that “the United Nations identifies long-term solitary confinement as a form of torture.”

The measures are intended to protect those who might otherwise interact with Tsarnaev from death or injury; however, the lawyers contend, “The government has not alleged that Mr. Tsarnaev has done or said anything since his arrest to commit violence, incite violence or engage in communications that pose a security threat.”

Feds argued in support of the restrictions restricting his access to mail, telephones and visitors, saying that three days after his April 19 capture in Watertown, Tsarnaev “reaffirmed his commitment to jihand” and told the FBI he hoped “his actions would inspire others to engage in violent jihad.”

Tsarnaev is accused of conspiring with his now-deceased brother, Tamerlan, 26, to set off a pair of crude homemade bombs at the Boylston Street finish line on April 15, killing three and wounding more than 260. The brothers are also accused of murdering MIT campus cop Sean Collier April 18 during a desperate and failed getaway.