It can be easy, given the steady drip-drip of news and intrigue related to the Mueller Inquiry, to lose sight of the bigger picture. By pleading guilty to lying to Congress, Donald Trump’s former fixer Michael Cohen, confirmed the extraordinary (though long suspected) information that the president lied to the public about the extent of his business interests in Russia.

According to Cohen’s plea agreement, Trump’s former lawyer lied to the Senate Intelligence Committee in January 2017 when he told them that a project to build a Trump tower in Moscow had been abandoned in January 2016, before the Iowa caucus and the first presidential primary. Cohen now says that he and “Individual 2” (presumably Cohen’s old friend, the Russian businessman and convicted stock swindler Felix Sater) continued negotiating with the Russian government over the property deal as late as June 2016, when Trump was on the cusp of winning the Republican nomination.

The plea agreement confirms that Cohen lied about other things too, including the extent of his contact with Russian officials over the project. Cohen revealed that in May 2016 he had agreed to travel to Russia to be introduced to either the Russian president Vladimir Putin or the Russian prime minister Dmitry Medvedev. He also made inquiries about Donald Trump visiting Russia.

The plea agreement states that Cohen lied to Congress to “minimise links” between Donald Trump and the Moscow Trump tower project and to give the false impression that the project ended before the Iowa caucus, in “hopes of limiting the ongoing Russia investigation”.

This is the first time Cohen has been charged under the Mueller Inquiry, which is investigating Russian interference in the US elections. In April this year investigators in the Russia probe referred Cohen’s case to the FBI, which raided his home and office as part of a criminal investigation into his personal and business interests. In August, Cohen pleaded guilty to tax evasion, bank fraud and breaking campaign finance laws by arranging hush payments to two women who say they had affairs with Trump.

Once one of Trump’s most loyal aides, Cohen turned on the president, telling the court in August that he had acted “under the direction of and in coordination with” the president to make the illegal payments to the women. He also offered to cooperate fully with the Mueller Inquiry, something that his legal team reportedly hopes will lead to more lenient sentencing for his criminal charges. He is due to be sentenced in around a fortnight.

Cohen’s plea deal increases the threat to Trump posed by the Mueller Investigation, which appears to be closing in on extensive ties between the Trump administration and Russian officials. Trump has predictably lashed out, telling reporters outside the White House that Cohen is “a weak person” and he has repeatedly attacked the Mueller Inquiry as a “witch hunt” and sought to limit its power. He has threatened several times to fire Mueller, and in November removed the attorney general Jeff Sessions, replacing him with a loyalist who wants to limit the investigation.

Cohen’s plea comes a day after Mueller’s investigators accused Trump’s former campaign manager Paul Manafort of breaching his plea deal by lying to them. Manafort is facing up to ten years in prison for lying about his political work in Ukraine, money laundering and cheating the US out of $15m in unpaid taxes.

The New York Times has reported that Manafort’s legal team also regularly briefed Donald Trump’s lawyers on their discussions with Mueller’s investigators, giving Trump’s lawyers inside knowledge of what avenues the prosecutors and pursuing and raising the likelihood that Manafort never intended to cooperate with Mueller, but has instead been hoping for a presidential pardon. Trump has said that he’s not taking the possibility of pardoning Manafort “off the table”, again highlighting the extent to which the president is willing to interfere in the work of the special counsel.

This also gives an indication of the extent to which Trump may be feeling the heat of the investigation, which has escalated in recent days. Mueller’s prosecutors are also said to be investigating possible links between senior Trump advisers and Wikileaks, the organisation that leaked Democratic campaign emails obtained by Russian hackers, ensuring that the Clinton campaign faced a steady stream of embarrassing leaks in the run-up to the presidential election.

While Trump likes to dismiss the Mueller investigation as slow moving and inactive, it’s actually proceeding rapidly. It has already indicted or extracted guilty pleas from at least 33 people, including 25 Russians and three Russian companies accused of hacking and leaking Democratic emails or operating “Russian troll farms” intended to influence the election.

Cohen is the fifth Trump adviser to be charged by Mueller. Manafort’s right-hand-man Rick Gates, a former Trump campaign aide, struck a plea deal after being indicted on similar charges to his boss. And Trump’s former national security adviser, Michael Flynn, has pled guilty to lying to the FBI over his contact with Russian officials, as has the former foreign policy adviser to the Trump campaign George Papadopoulos.

So who’s next? Mueller’s investigators do not speak to the press, but we know that prosecutors are interested in potential between Donald Trump and the political operative Roger Stone over Wikileaks. And thanks to a mistake in a US court filing it is widely believed that US authorities may be planning to press criminal charges against Wikileaks’ founder Julian Assange. Don’t look away.