This article is more than 1 year old

This article is more than 1 year old

Donald Trump lashed out again on Saturday on the subject of impeachment and the former special counsel Robert Mueller’s testimony on Capitol Hill, which the president called “the greatest display of ineptitude [and] incompetence that the Halls of Congress have ever seen”.

Trump 'rat-infested' attack on Elijah Cummings was racist, Pelosi says Read more

“Truth is, he had no facts on his side,” the president tweeted on Saturday. “Nothing he could do!”

Mueller appeared before the House judiciary and intelligence committees on Wednesday.

As promised, he discussed plentiful facts about Russian election interference, links between Trump and Moscow and instances of potential obstruction of justice by the president.

But he did not stray beyond the contents of his 448-page report, which was published with redactions in April.

That meant that while Mueller repeated that he did not find evidence of a conspiracy between Trump and Moscow, he also repeated that he did not exonerate the president over matters of obstruction of justice.

Amid widespread discussion of the 74-year-old former FBI director’s halting performance and uncertain demeanour, the Washington Post reported on Saturday that “some lawmakers are privately wondering whether there was some truth to … rumours” that Mueller “might not be as sharp as he once was”.

We may decide to recommend articles of impeachment at some point, we may not, it remains to be seen Jerrold Nadler

A spokesman for Mueller declined to comment, the Post said.

Trump seemed to seize on such reports: “The [Democrats] are now coming out of shock from the terrible Mueller performance, and are starting to spin impeachment all over again. How sick [and] disgusting and bad for our country are they. What they are doing is so wrong, but they do it anyway. [Democrats] have become the do nothing party!”

As the House went into recess on Friday for a six-week summer break, more than 100 Democrats had come out in support of taking steps toward impeachment.

No formal process to remove the president has been initiated but on Friday the House judiciary committee, which would initiate proceedings, filed a new lawsuit in an effort to obtain secret grand jury material underlying Mueller’s report. The suit mentioned the word impeachment 76 times.

The committee member Eric Swalwell said: “This is an impeachment investigation [about] whether we should recommend articles of impeachment to our caucus.”

The committee chair, Jerrold Nadler of New York, said before Mueller’s testimony there was plentiful evidence Trump had committed “high crimes and misdemeanours”, the constitutional standard for impeachment. On Friday, though, he said “too much has been made of the phrase ‘impeachment inquiry’.

“We are using our full Article I powers to investigate the conduct of the president and to consider what remedies there are,” Nadler said, referring to the constitution. “Among other things we will consider are, obviously, recommending articles of impeachment.”

He added: “We may decide to recommend articles of impeachment at some point, we may not, it remains to be seen.”

At her weekly news conference, the House speaker, Nancy Pelosi, said: “We will proceed when we have what we need to proceed, not one day sooner.”

Play Video 2:14 Democrat leaders call Mueller testimony 'historic' but shy away from impeachment – video

The new court petition is among a half-dozen legal actions pursued by House Democrats, who contend that Trump is obstructing their constitutional duty to conduct oversight by withholding documents and preventing witnesses from testifying.

House Democrats seek access to Mueller's grand jury evidence Read more

Senior figures including Pelosi have noted that the third article of impeachment against Richard Nixon was his obstruction of Congress. The 37th president resigned before he was officially impeached.

Next week, Nadler is expected to file a lawsuit to try to enforce a subpoena against Donald McGahn, the former White House counsel and a key Mueller witness. It challenges the White House claim that its former employees have “absolute immunity” from testifying before Congress.

After Mueller testified, Pelosi told Democrats that if they wanted to come out publicly in favour of impeachment, to do it in a way that did not make it a moral imperative. The next morning, she told lawmakers to say what they wanted on the subject but in way that did not challenge other Democrats’ views.

Pelosi’s comments were relayed to the Associated Press by three people unauthorised to speak publicly. Some Democrats grumbled that the investigations were becoming “endless”, one source said. But others said Democrats were elected in large part because voters want them to stand up to Trump.