An official at the National Republican Senatorial Committee told lobbyists and donors on Thursday that candidates are welcome to skip the Republican convention in July and instead focus on their own races, according to a New York Times report citing anonymous sources.

The Times reported:

In a new sign of the Republican Party’s reservations about Mr. Trump, the top strategist in charge of defending Republican control of the Senate said in a briefing for lobbyists and donors on Thursday that the party’s candidates should feel free to skip the nominating convention in Cleveland in July. The strategist, Ward Baker, the executive director of the National Republican Senatorial Committee, said conventions were a distracting spectacle every four years, according to two people who attended the briefing, and who spoke on the condition of anonymity about the private session. Mr. Baker, the attendees said, told Republican lawmakers that they would be better off talking to voters in their home states.

A spokeswoman for the NRSC, Andrea Bozek, told the Times that each campaign can make its own decision about attending the convention.

The reported comments from the NRSC show that Republicans are painfully aware of the potential negative impact Donald Trump’s place at the top of the ticket could have on important House and Senate races in November. Numerous vulnerable Republican lawmakers up for re-election in 2016, including Sen. Mark Kirk (R-IL), have said that they will skip the July convention.