As congressional Republicans prepare to gather in Philadelphia for their annual retreat, they are dealing with an irritation that has become familiar over the past year and a half: Donald Trump.

Although the first days of the Trump administration have been marked by a significant number of policy wins for the GOP, ranging from moves to revive the Keystone XL and Dakota Access pipelines to new limitations on government funding for abortion and the initial steps towards repealing Obamacare, none of those topics have dominated headlines since his inauguration on Friday.

Instead, the new president has continued to indulge the penchant for controversial and often demonstrably untrue statements that marked his time on the campaign trail.

Trump spent the aftermath of his inauguration litigating the size of the crowds that came to see him take office in front of the memorial wall at the CIA. The president has since told congressional leaders that there was massive voter fraud in the 2016 election, with between 3 million and 5 million people casting illegal ballots, a claim unsupported by evidence. After being drafted in to harangue the press with a series of falsehoods over the inauguration’s crowd size, Trump’s press secretary, Sean Spicer, reiterated the president’s fraudulent claims at the White House press briefing on Tuesday, telling reporters the president “does believe that. He has stated that before. I think he stated his concerns of voter fraud and people voting illegally during the campaign and he continues to maintain that belief based on studies and evidence that people have presented him.”

The statements brought endless irritation to Republicans on Capitol Hill on Tuesday, who were hoping to focus on policy after an election driven and dominated by Trump’s off-the-cuff remarks. Some, such as Senator Rand Paul of Kentucky, blamed the media for the attention that Trump’s statements had gotten. “There’s a lot in the media that are sort of stuck on it. The media would be better served to look at some forward-thinking things we needed to do with Obamacare and tax reform,” said the libertarian former presidential rival of Trump.

When asked for his thoughts on Trump’s voter fraud claims, Senator Bob Corker, chair of the Senate foreign relations committee, said: “He has a whole swathe of people I saw that were sworn in as his advisers at the White House the other day, and that’s their job.”

Corker, a longtime Trump supporter who was considered as a possible candidate both for vice-president and secretary of state, said that the comments had “no effect” on his job. Instead, he suggested it was good for the media and “great for all of you selling newspapers and having television ratings”.

Senator John McCain of Arizona, the GOP’s 2008 presidential nominee, became exasperated when asked about Trump’s remarks. “Long ago I gave up talking about what the president talks about, my concern is what he does and I’m pleased he’s got a national security team, many of whom I have known for many years … that’s my priority, I cannot respond to his statements which I don’t have any knowledge of.”

Perhaps the most typical response came from Senator Tim Scott of South Carolina who, when asked about Trump’s comments on voter fraud, said: “I don’t think about it because it’s not that important to me.” When asked by reporters if he knew of any evidence of voter fraud, Scott simply gave a shrug.

Democrats responded by trying to put the onus on their Republican colleagues for not condemning their party’s leader. “When these falsehoods are told, our Republican colleagues have an obligation to reject them, not to skirt around them,” said the Senate minority leader, Chuck Schumer, on Tuesday. However, 18 months after Trump first announced his presidential candidacy, Republicans are well practiced at evading questions about his controversial remarks. But they will dog the retreat.

And, as much as Republicans would like to tout policy priorities such as tax reform and repealing Obamacare, let alone a historic visit from the British prime minister, Theresa May, who is speaking at the retreat on Thursday, it is likely that Trump’s penchant for drawing attention, both positive and negative, will continue to loom over the event.