Centre of attention: Donald Trump junior may have given those investigating his father's campaign their smoking gun. Credit:New York Times Here's the gist of what has been reported, much of it verified by emails to and from Trump jnr: He was told that one of the Trump family's former Russian business associates had been contacted by a senior Russian government official who was offering to deliver dirt on Hillary Clinton to the Trump campaign, which at the time was lagging Clinton by a few points in opinion poll averages. These Russian documents "would incriminate Hillary and her dealings with Russia and would be very useful to your father", the first email to Trump jnr said. It went on: "This is obviously very high level and sensitive information but is part of Russia and its government's support for Mr Trump." Most surprising in the emails, copies of which Trump jnr released once he was informed that the Times was about to publish them, is the absence of any surprise on the part of presidential nominee's son: "If it's what you say I love it especially later in the summer," he replied within minutes. Trump jnr shared the emails with Kushner and Manafort, who seemingly had no hesitation in accepting the Russian offer – and on June 9 all three attended a meeting at Trump Tower with Kremlin-associated lawyer Natalia Veselnitskaya.

Emin Agalarov, son of Russian tycoon and Trump business associate Aras Agalarov, is named in the emails sent to Donald Trump junior as having made the proposal. Credit:AP The emails make it impossible for Trump jnr to deny that he understood this was going to be a meeting with a Russian operative who was offering to help his father's campaign. And Kushner and Manafort's willingness to attend the meeting is the strongest evidence to date of the Trump campaign's willingness, even eagerness, to accept help from Moscow. If investigators are looking for evidence of intent as they firm up charges of conspiracy, the willingness of the three to attend the meeting might be just the thing. Kremlin-linked lawyer Natalia Veselnitskaya met with Donald Trump jnr and Jared Kushner. Credit:AP There will be questions about any quid pro quo that was discussed or implied in the meeting.

Contrary to the "Clinton dirt" and "Russian government support for Trump" tenor of the emails, Trump jnr's initial explanation was that the meeting "primarily" discussed stalled US adoptions of Russian babies. But subsequently he and Veselnitskaya, the Russian lawyer, confirmed that they did discuss US sanctions on Russian human rights offenders. Miss Venezuela 2013, Gabriela Isler, poses with Miss Universe organiser Donald Trump after the Grand Finale held at the Crocus City hall in Moscow. Credit:EPA Russia halted the adoptions in retaliation for the sanctions, so even if it wasn't stated bluntly, in raising the adoptions issue Moscow was looking for sanctions relief – which the Kremlin might have anticipated as a reasonable payoff for the Clinton dirt. Similarly, it doesn't take a leap of investigative imagination to wonder if the offer of Russian help, so enthusiastically embraced by Trump jnr, included the dumping just weeks later by WikiLeaks of thousands of embarrassing emails, which US intelligence agencies say were hacked from Democratic Party computers by Russian operatives – at the behest of the Kremlin. As so often is the case in politics, there is the question of the cover-up.

Is it plausible that the three – Trump jnr, Kushner and Manafort – took time out from the campaign after such an enticing invitation, without informing then-candidate Trump, whose aides say he was unaware of the meeting until this week's blow-up? There are reports too that the President took part in a council of war as Air Force One flew back from Germany on Saturday, which debated just how transparent his son should be in his response to the Times' first inquiries about the June 2016 meeting – and that Trump snr signed off on a statement that by omission and commission concealed the truth. On at least eight occasions since the June 2016 meeting, various Trumps have denied that such a meeting might have happened – just weeks after it did happen, Trump jnr appeared on CNN, rejecting a suggestion that the Russians were attempting to aid his father's campaign as "disgusting" and "phoney". Trump snr has repeatedly denounced charges of collusion as "fake news" and a "total hoax". That line of defence has now been blown out of the water.

Then there's the ripple effect. For now most of the attention is on Trump jnr. But in the coming days, questions are sure to be asked about the role of Kushner, who sits at the President's right hand in the White House – and this is another of those meetings with foreigners that Kushner forgot to declare while being vetted for a security clearance that gives him access to the country's most tightly-held intelligence secrets. Jeffrey Jacobovitz, a white-collar attorney and one-time defender of the Clinton White House, said: "It's as close as you can get to a smoking gun … If [Trump jnr] received an email in advance saying, 'This is coming from the Russian government', he's certainly knowledgeable about where the information is coming from. "And he attempts to attend a meeting with the hope and intent to obtain inside dirt on Hillary Clinton. That would go a long way in trying to determine whether it's conspiracy … It's not as if he walks into the meeting and he's surprised by what he's hearing." Barak Cohen, a former federal prosecutor: "The emails tell me that he's aware that the Russian government is trying to influence the election in favour of Trump, and they also indicate an intent, at least on the part of Donald Trump jnr, to entertain the idea of working with the Russians in their efforts."

Jens David Ohlin, associate dean of Cornell Law School: "It's a shocking admission of a criminal conspiracy. The conversation will now turn to whether President Trump was personally involved or not. But the question of the campaign's involvement appears settled now. The answer is yes." As some defenders took to describing Trump jnr as a "kid" who was new to the game of politics, former Obama ambassador to Moscow Michael McFaul was unflinching: "It wasn't naivete. It was, 'Oh, they have some dirt on our opponent and I'm eager to receive it.' Nobody thought to think, 'Well, how did they obtain that? Is this coming from the Russian government, Russian intelligence?' Those are the kinds of obvious questions that should have been asked, in my opinion." Democratic senator and Clinton vice-presidential candidate Tim Kaine listed the possible charges: "Nothing's proven yet, but we're now beyond obstruction of justice in terms of what's being investigated. This is moving into perjury, false statements and even potentially treason." And how are Republicans responding? On Capitol Hill, many flee rather than allow themselves to be confronted by reporters – one of a few exceptions was senator Lindsey Graham, who said: "Anytime you're in a campaign and you get an offer from a foreign government to help your campaign, the answer is 'no'."

Insisting that Trump jnr "definitely" must testify before the various Russia investigations, Graham added: "That email was disturbing … very problematic." But there is a Republican plot in the making to discredit reporters working on the Donald jnr story – the plan is to analyse their work over the years in a search for mistakes and signs of partisan bias, which will be fed to outlets that are part of the Trump media cheer squad. President Trump is reportedly fuming – lashing out at the army of lawyers recruited by various members of the first family and the administration to fend off the seemingly unstoppable "Russia thing". The usual factional war and chaos of the White House is said to be intensifying as aides form a "circular firing squad" to blame each other for the leaks that spawned the Times' remarkable reports. Trump apparently genuinely believed that his trip to Europe last week, and in particular his long sit-down with Vladimir Putin, would allow his administration to "move forward". Loading

And even as the Trump jnr story broke, others in the administration agreed with his assessment that the myriad probes of the Russian election meddling and of possible collusion by some in his campaign team was driven by Democrat sour grapes over losing the election – White House chief of staff Reince Priebus went on Fox News to denounce the first accounts of the Trump jnr-Kushner-Manafort meeting with the Russian lawyer as "a big nothingburger". Not so – this is one of the meatiest burgers that's been served up in Washington in a long time.