The White House has unveiled Donald Trump’s legal team for his Senate impeachment trial, a list of attorneys whose own ageing controversies threaten to overshadow their efforts to defend the president.

As the impeachment process enters a major new phase next week, Trump’s defense team will include Alan Dershowitz, known for defending the convicted sex offender Jeffrey Epstein, and Kenneth Starr, the dogged prosecutor who led the investigation that culminated in the 1998 impeachment of former president Bill Clinton and lost a university post in 2016 for mishandling sexual assaults on campus.

“This is definitely an ‘are you fucking kidding me?’ kinda day,” tweeted Monica Lewinsky, whom Starr reportedly threatened with criminal charges in 1998 to get her to testify in forensic detail about her relationship with Clinton, which became a central focus of the impeachment inquiry against him.

Dershowitz sought to deny in a radio interview Friday afternoon that he was a “member of the Trump legal team”, saying that he would speak on behalf of the US constitution. But he has been invited to speak by Trump, he is expected to speak during the time allotted to Trump’s defense and he will make an argument that effectively and exclusively encourages the president’s acquittal.

The question of how Trump’s legal team will defend him sharpened as the House of Representatives, which impeached Trump last month, handed over the process to the Senate, where a trial will culminate in a vote on whether to remove Trump from office.

The trial is expected to last at least two weeks and could feature testimony by close Trump advisers and former advisers who have yet to speak out on allegations that Trump withheld military aid and a White House meeting from Ukraine in an effort to manufacture damaging headlines about the former vice-president Joe Biden, a political rival.

Trump was impeached for abuse of power in the scheme and for obstructing the efforts of Congress to investigate it.

A two-thirds majority of senators present would be required to remove Trump from office. Most political observers think he is safe, given the lockstep loyalty of Republicans, who hold a majority in the Senate.

But an element of unpredictability in the impeachment trial means that neither Trump nor his Republican surrogates are quite in control of the president’s political fate.

If Democrats can recruit just a few Republican senators to join their call for witnesses to testify at the Senate trial, new details about Trump’s attempt to extract a “favor” from Ukraine could emerge, with unknown consequences for his approval rating as he seeks re-election in November.

A majority of American voters have consistently said in opinion polls that Trump abused his power and deserves impeachment, including in polling directed by conservative media organizations.

Trump’s legal team will be led by the White House counsel, Pat Cipollone, and by Jay Sekulow, a longtime personal lawyer to Trump. Also defending Trump will be Pam Bondi, a White House impeachment adviser; Jane Raskin, who defended Trump during the Robert Mueller inquiry into Russian interference in the 2016 US election; and Robert Ray, who was on the independent counsel team with Starr in the Clinton era.

As White House counsel, Cipollone’s strict role is to give legal advice pertaining to the presidency, as opposed to defending Trump personally. But he has been embroiled in impeachment since he signed an October letter declaring that the White House would not turn over documents or otherwise cooperate with impeachment investigators – a letter that Democrats later made exhibit A of Trump’s obstruction of Congress.

Dershowitz, 81, a retired professor of constitutional law at Harvard University, and Starr, 73, formerly president of Baylor University in Texas, have demonstrated their loyalty to Trump in frequent appearances on cable television.

But their presence in the Senate chamber for Trump’s impeachment trial could complicate certain features of Trump’s defense, including the attempt by top Republicans to block new witness testimony.

In arguing for witnesses, Democrats will be able to point to the extraordinarily wide net for testimony that Starr cast in his five-year investigation of Clinton, which included interviews with ex-boyfriends of Lewinsky and the White House window washers.

Continuing controversies attached to Starr and Dershowitz, both of whom worked as lawyers for Epstein, who killed himself in a New York jail cell last year, could distract from the effort to exculpate Trump.

Starr stepped down as president of Baylor in 2016 following an investigation into allegations that he failed to respond to a sexual assault crisis involving the school’s football team. Starr was not found guilty of wrongdoing and the two sides described the separation as a mutual agreement.

Dershowitz, a prominent first amendment litigator, found deeper notoriety as a friend and adviser to Epstein.

One of Epstein’s victims has accused Dershowitz in court of sexually abusing and defaming her; in November, he countersued, denying any misconduct and claiming that he was being defamed and subjected to emotional distress.

Dershowitz has said he was “shocked” to learn the “extent” of Epstein’s crimes and said Epstein’s case was the one from his career that he regretted taking.

Apart from Lewinsky, the announcement of Trump’s team was met with degrees of disgust and mirth.

David Frum, a former speechwriter for George W Bush, tweeted: “Cannot believe it’s possible to hire this calibre of representation without paying a nickel for it.”