Rep. Jason Chaffetz, chairman of the House Oversight and Government Reform Committee. (Andrew Harrer/Bloomberg News)

When you call the House Oversight and Government Reform Committee, which has primary responsibility for any investigations in Congress related to President Trump, you get voice mail.

Here’s what it says: “If you would like to provide information or make an inquiry relating to President Donald Trump, please press 1.”

If you press 1, this is the message you receive: “Because of high call volume, we are unable to answer your call at this time.” If you leave your name, number and “any information you would like to provide,” you get a promise that your message will be “reviewed as soon as possible.”

Callers are also told they can press 2 for “all other matters” or to speak with the staff of the panel’s chairman, Rep. Jason Chaffetz (R-Utah).

So far, Chaffetz’s committee says it is not planning to probe anything related to Trump as part of its oversight mandate, despite Democratic pressure. But even if the lawmakers wanted to, staffers might be overwhelmed by the feedback collected on the committee’s voice mail.

The situation on the Oversight Committee isn’t much different from what other Capitol Hill offices have faced since Trump was inaugurated on Jan. 20. A flood of phone calls about the president and his early policies is jamming phone lines and prompting lawmakers to set up special procedures for handling calls.

Though it’s impossible to know exactly how many callers support or oppose Trump’s actions, aides from both sides of the aisle agree that the volume of calls is up — way up — since the weekend, when the administration announced its immigration ban affecting people from seven majority-Muslim countries.

Across the Hill, administrative officials are trying to increase the capacity of the phone lines to allow more calls to get through.

“For now, callers should wait a little while and try again if they want to complete the call,” Dan Weiser, communications director for the House’s chief administrative officer, Philip G. Kiko, wrote in an email.

But that might be hard.

On Monday, busy signals greeted callers trying to reach Sens. Bernie Sanders (I-Vt.) and Lindsey Graham (R-S.C.), and Senate Minority Leader Charles Schumer (D-N.Y.). Calls to the offices of Sens. John McCain (R-Ariz.) and Susan Collins (R-Maine) rang through, then dropped. Callers to the officers of Sens. Ben Sasse (R-Neb.) and Elizabeth Warren (D-Mass.) were directed straight to voice mail.

Aides attributed all these issues to technical problems related to the high volume of calls.

“The phones have been hot for the last couple of weeks,” Sanders spokesman Josh Lewis-Miller said in response to an inquiry.

“My understanding is the main switchboard is overloaded. Calls on Cabinet and executive order,” emailed Matt House, a spokesman for Schumer, referring to Trump’s travel ban.

Many of the calls seem to have been orchestrated by liberal organizations. D.C.-based Revolution Messaging launched a mobile platform it says has directed an average of 10,000 protest calls to Congress every day since Jan. 20. Congressional aides attribute other calls to the directions given to crowds at the women’s marches following Trump’s inauguration and other demonstrations around the country.

At some marches, according to attendees, organizers handed out specific congressional numbers printed on slips of paper. One of those numbers — the Capitol’s main switchboard — was plugged with hold music for hours Monday.

“We are seeing a heavier-than-normal amount of constituent calls but an extremely high amount of out-of-state calls, which make up two-thirds to 90 percent of our overall call volume,” said Annie Clark, spokeswoman for Collins.

Speaker Paul Ryan (R-Wis.), too, appears swamped. “We’re sorry, but your call cannot be completed at this time,” said an automated message. “Please hang up and try your call again later.”

Lawmakers insist that using voice mail is not a move to ignore calls. But for some, the way the phones are being answered — or not answered — has become a liability.

On the Oversight Committee, the situation has happened before — in mid-November, the committee was overwhelmed with calls after several viral Facebook posts called for it to launch an investigation into Trump’s finances.

And Sen. Ron Johnson (R-Wis.) is on the defensive over claims by Rep. Gwen Moore (D-Wis.) that his D.C. office has been turning off its phones.

“This is a disturbing/ongoing trend,” Moore tweeted Monday. “I’ll do my best to help constituents reach [Johnson] for casework but there’s only so much we can do w/ legislative jurisdictions.”

Johnson replied less than an hour later. “Our phones are certainly on & being answered,” he wrote on Twitter. “We’re here for all Wisconsinites.”

We tested the line just to make sure.

The first call to Johnson’s office at noon Tuesday produced a fast busy signal, indicating the number could not be reached. A second call went to voice mail.