WASHINGTON, DC, USA (AP) — Speaker Nancy Pelosi said yesterday that people have a “spring in their step” after the House impeached President Donald Trump, but she insisted the Senate must provide more details about the expected trial in that chamber before she agrees to send the House charges over.

Pelosi’s unexpected procedural delay — looking for leverage in trial arrangements — was getting a sour response from Senate Majority Leader Mitch McConnell and from Trump himself.

McConnell said Democrats are “too afraid” to send the charges to the Senate, where Trump would be expected to be acquitted by the Republican majority. Trump tweeted, “Now the Do Nothing Party want to Do Nothing with the Articles.” He claimed that if the Democrats didn’t transmit the articles of impeachment “they would lose by default”, though there is no constitutional requirement to send them swiftly, or at all.

Some White House officials argued that delaying the trial indefinitely actually would play to their advantage and help them make the case that Democrats have manipulated the impeachment process.

The trial is expected to begin in January.

Pelosi was upbeat the morning after the historic vote that made Trump only the third president in US history to be impeached. The House impeached Trump on two charges — abusing his presidential power and obstructing Congress — stemming from his pressure on Ukraine to announce investigations of his political rival as Trump withheld US aid.

“We’ve been hearing from people all over the country,” Pelosi told reporters at the Capitol. “Seems like people have a spring in their step because the president was held accountable for his reckless behaviour.”

Pressed about next steps, Pelosi wouldn’t say. Democrats are insisting on more witnesses, testimony and documents than McConnell appears willing to provide before they name the House “managers” who would prosecute Trump in the Senate.

“The next thing will be when we see the process that is set forth in the Senate,” Pelosi said. “Then we’ll know the number of managers we may have to go forward and who we would choose.”

She said the previous night, “So far we haven’t seen anything that looks fair to us. So hopefully it will be fair. And when we see what that is, we’ll send our managers.”

The Democratic speaker and the top Senate Democrat, Chuck Schumer of New York, met privately yesterday at the Capitol after Republican Senate Leader McConnell signalled, in the strongest terms yet, that his chamber intended to hold a swift trial and acquit the president of both charges.

McConnell denounced the “most unfair” House impeachment and reassured Trump and his supporters that “moments like this are why the United States Senate exists”.

As for what the Senate would do, he said, “It could not be clearer which outcome would serve the stabilising, institution-preserving, fever-breaking role for which the United States Senate was created and which outcome would betray it.”

McConnell described Trump’s impeachment as “the most-rushed, least-thorough and most unfair impeachment inquiry in modern history”.

Fighting back and using McConnell’s own words, Schumer said the Republican leader was plotting the “most rushed, least-thorough and most unfair” impeachment trial in history by declining to agree to call witnesses including former Trump National Security Adviser John Bolton, who declined to testify before the House.

“McConnell claimed the impeachment was motivated by partisan rage,” said Schumer. “This from the man who said proudly, ‘I am not impartial’.

“What hypocrisy.”

Pelosi said that McConnell “says it’s OK for the foreman of the jury to be in cahoots with the lawyers of the accused. That doesn’t sound right to us”.

McConnell was meeting later yesterday with Schumer to begin negotiations on how to conduct a Senate trial. The two leaders have a tense relationship, and McConnell holds a tactical edge if he can keep his 53-member Senate majority united.

Complicating any decision to delay are House Democrats’ arguments in recent weeks that Trump’s impeachment was needed “urgently”, arguing his actions were a threat to democracy and the fairness of the upcoming 2020 election.