Rally for thousands of diehard supporters held on same day news emerged that special counsel has set up panel to examine evidence of alleged collusion

Donald Trump has sought to rally thousands of diehard supporters against the investigation into his campaign’s alleged collusion with Russia – on the same day news emerged that the special counsel, Robert Mueller, has convened a grand jury in the case.

“They’re trying to cheat you out of the leadership that you want with a fake story,” Trump told a rally in Huntington, West Virginia.

Quick guide Who are the key Russian players in the Trump collusion accusations? Show Hide Natalia Veselnitskaya A Russian lawyer whose work has focused on ending US sanctions on Russia and who met with Trump representatives Donald Trump Jr, Jared Kushner and Paul Manafort at Trump Tower in June 2016. Read further. Sergey Kislyak Until recently, the Russian ambassador to the US. A hub for contacts with Trump representatives including Kushner, attorney general Jeff Sessions, former national security adviser Michael Flynn and the president himself. Read further. Sergey Gorkov The Kremlin-connected head of Russian state investment bank Vnesheconombank. He met with Kushner during the presidential transition, but “no specific policies were discussed”, according to Kushner. Read further. Dimitri Simes President of the Center for the National Interest, a Washington thinktank, which hosted an April 2016 foreign policy speech by Trump. Trump, Sessions and Kushner appear to have met with Kislyak at the event, although both Kushner and Sessions have said any meeting was only in passing and they don’t recall what was discussed. Read further.

By Tom McCarthy

The concerted effort could be a sign that the White House is realising the full gravity of the situation. Mueller, appointed special counsel in May following the dismissal of the former FBI director James Comey, has recruited more than a dozen investigators, including current and former justice department prosecutors with experience in international bribery, organised crime and financial fraud.

On Thursday, it was reported – first by the Wall Street Journal, but later by other outlets including the Associated Press – that Mueller is using a grand jury in Washington, meaning he could subpoena witnesses and records in the coming weeks and months.

The use of a grand jury, a standard prosecution tool in criminal investigations, suggests that Mueller and his team of investigators are likely to hear from witnesses and demand documents in the coming weeks and months.

In what might be seen as a bid to weaponise his populist base, Trump told the crowd in Huntington, a coal country stronghold where he beat Hillary Clinton by 42 percentage points: “Most people know there were no Russians in our campaign; there never were. We didn’t win because of Russia. We won because of you.”

The crowd, many with “Make America great again” hats or signs, erupted in vociferous cheers. Trump continued: “We won because we totally outworked the other side. We won because of millions of patriotic Americans voted to take back their country.”

The president asked mockingly: “Have you seen any Russians in West Virginia or Ohio or Pennsylvania? Are there any Russians here tonight, any Russians? They can’t beat us at the voting booths so they’re trying to cheat you out of the future and the future that you want. They’re trying to cheat you out of the leadership that you want with a fake story that is demeaning to all of us and most importantly demeaning to our country and demeaning to our constitution.”

Senators launch bipartisan effort to ensure Trump cannot fire Mueller Read more

Trump’s rhetoric at a 9,000-person capacity arena on Thursday echoed rallies during the election campaign where he claimed the system was rigged against him. This time he appeared to be scattering seeds of doubt about the investigations by Mueller and two congressional committees into whether there was collusion between Russia and Trump’s presidential campaign.

“I just hope the final determination is a truly honest one, which is what the millions of people who gave us our big win in November deserve and what all Americans who want a better future want and deserve,” the president added ominously.

“Democrat lawmakers will have to decide. They can continue their obsession with the Russian hoax or they can serve the interests of the American people. Try winning at the voter booth. Not going to be easy, but that’s the way you’re supposed to do it.”

Q&A What is a grand jury? Show Hide Grand juries are used in only a handful of countries. In the US, they are normally made up of about 16 to 23 members of the public rather than the usual 12, hence “grand” jury. They are also held in secret – the fact that one has been convened is not even officially acknowledged. Unlike in ordinary courts, witnesses are not allowed to have lawyers present and federal prosecutors often treat them as fishing expeditions, where investigators question witnesses under oath for hours hoping to trip them up and make them perjure themselves. Lawyers, who sit outside, implore witnesses to consult with them before answering even seemingly easy questions.

Trump spared the media his usual broadsides and instead focused on the Democrats, whom he claimed were trying to find an excuse for “the greatest loss in the history of American politics”. Prosecutors should be looking for former secretary of state Hillary Clinton’s 33,000 emails, he added, prompting thunderous cheers and chants of “Lock her up!” – some nine months after the election.

The prolonged denial of links to Moscow signalled a shift in strategy for Trump, who rarely dwells on the issue during rallies, where few supporters seem concerned. His daughter-in-law, Lara Trump, also brought it up during a short speech, calling it a “crazy story about Russia”. And the West Virginia governor Jim Justice, announcing his defection from the Democrats to the Republicans, told the crowd: “Have we not heard enough about the Russians? I mean, to our God in heaven, think about it: the stock market’s at 22,000 and this country has hope and we’re on our way.”

The defense attorney John Dowd told the Associated Press: “With respect to the news of the federal grand jury, I have no reason to believe that the president is under investigation.”

Ty Cobb, special counsel to the president, said he was not aware Mueller had started using a new grand jury. “Grand jury matters are typically secret,” Cobb told the Associated Press. “The White House favours anything that accelerates the conclusion of his work fairly … The White House is committed to fully cooperating with Mr Mueller.”

It was unclear how the Washington grand jury was connected to the work of a separate grand jury in Alexandria, Virginia, that has been used to gather information on Trump’s former national security adviser Michael Flynn, who is under scrutiny over his ties to Moscow.

Steve Williams, the mayor of Huntington, criticised Trump’s claim that the Russia story was a hoax. “It obviously isn’t because Mueller is announcing today that a grand jury has been impaneled. Methinks he does protest too much.”

Trump’s speech in the city was a wasted opportunity, Williams added. “I thought it was a 2016 campaign rally. I expected some discussion about the opioid crisis, particularly since the president’s commission’s report came out a couple of days ago. I was hoping he would declare a national emergency.”