The firing of James Comey by Donald Trump came just as the investigations into the President’s alleged clandestine links with Russia were gaining fresh impetus, after a period when they had been stymied through White House pressure.

The inquiries by Mr Comey’s FBI and Congress had seen a marked upturn in activity in recent weeks, indicating that the drive to uncover if Mr Trump was the “Muscovite Candidate” in last year’s election was not going to go away. This has been reinforced by reports that Mr Comey asked for further resources for his investigation in the days before he was forced out.

The senate minority leader, Chuck Schumer, was among those who raised questions about the timing of Mr Comey’s dismissal. “Were these investigations getting too close to home for the President? This does not seem to be a mere coincidence,” he pointed out.

It has emerged that just hours before Mr Comey was sacked Federal prosecutors issued grand jury subpoenas to associates of Lieutenant General Michael Flynn, who had to resign as Mr Trump’s national security adviser after his connections with Moscow were exposed.

This is a highly significant development, with grand juries having wide-ranging powers to compel hostile witnesses to appear before them, demand and receive confidential documents and issue criminal indictments.

It has also emerged that a Senate Committee has asked the Treasury’s criminal investigation division for any relevant financial information related to Mr Trump, his associates and his campaign aides. White House spokesman Sean Spicer, meanwhile, was forced to disclose that the President has hired a private Washington law firm to write to the Committee over his alleged Russian links.

Mr Comey’s demise also comes after revelations that Barack Obama had personally warned Mr Trump against hiring Lt Gen Flynn because of the security risk he posed, and Sally Yates, in her post as US Deputy Attorney General, had warned the White House that the new President’s national security adviser had lied about his meetings with the Russian ambassador in Washington, Sergey Kislyak.

Ms Yates was fired by Mr Trump soon after he came to office. It was said at the time that this was due to her refusal to enforce his ban on travellers from a number of Muslim countries, pointing out that it was unconstitutional. But her involvement in the Flynn affairs may also, it is now believed, have played a part in the decision being made. After her testimony to the Senate Judiciary Subcommittee on Crime and Terrorism about Lt Gen Flynn on Monday, Mr Trump abused her on Twitter.

The White House had also sought to stop Ms Yates from giving evidence before the House committee looking into links between Mr Trump and associates and Russia. The hearing for her testimony was cancelled abruptly by Devin Nunes, the Republican chairman of the Committee.

Mr Nunes was among a number of Republican Congressmen who appeared to be successfully thwarting the Russia investigations, to the frustration of the Democrats as well as a number of Republicans.

But he had to recuse himself from the inquiry after it was disclosed that he was taking information to the Trump team before placing it before the Committee. Mr Nunes is now the subject of an ethics investigation.

The removal of Mr Nunes gave the House investigation a boost. Adam Schiff, the ranking Democrat in the Committee said he was receiving cooperation from the new Republican chairman, Mike Conway. “We are making progress. Mike Conway and I have worked together in a non-partisan, very matter of fact way,” he stated.

“We are back to scheduling our witnesses… We are getting new documents from the Intelligence Community: so things are moving in a very positive direction.”

Meanwhile a separate Senate investigation into the Kremlin links has also stepped up a gear. The size of the research team was increased and last week a number of Trump campaign aides were asked to hand over notes and records of meetings with Russian officials.

Why did Donald Trump fire James Comey?

Among those who received the demands were Carter Page, who had been a foreign policy adviser to Mr Trump, and Roger Stone, a confidant and informal adviser.

Mr Page had acknowledged that he had been the target last year of a Foreign Intelligence Surveillance Act (Fisa) order, obtained by the FBI, something normally issued when the law agencies can show probable cause that the subject of the surveillance was in the service of a foreign power. One of the areas being examined is his possible links with Igor Sechin, the head of Russia’s state-run oil company, Rosneft, and a close associate of Vladimir Putin.

There are also Congressional inquiries into Paul Manafort, who had to resign as Mr Trump’s campaign manager due to his links with Moscow-backed figures. Mr Manafort had formerly worked as campaign manager for Viktor Yanukovych, the former Ukrainian President now in exile in Russia.

Prosecutors in Kiev now want to question Mr Manafort about his alleged receipt of vast sums of money from Mr Yanukovych and say they have requested help from James Comey for their investigation.

It is seen as a sign of the Trump team’s nervousness about what may unfold that it appears to be trying to distance itself from Mr Manafort. At a recent briefing to journalists, the White House spokesman Sean Spicer brought up Mr Manafort’s name unprompted, and claimed, to general incredulity, that “he played a very limited role, [for a] very limited amount of time” in the presidential campaign.

Donald Trump's first 100 days: in cartoons Show all 33 1 /33 Donald Trump's first 100 days: in cartoons Donald Trump's first 100 days: in cartoons Donald Trump's first 100 days in office were marred by a string of scandals, many of which caught the eye of the Independent's cartoonists Donald Trump's first 100 days: in cartoons Trump's first 100 days have seen him aggressively ramp up tensions with his nuclear rivals in North Korea Donald Trump's first 100 days: in cartoons Mr Trump has warned of a "major, major conflict" with the pariah nation lead by Kim Jong Un Donald Trump's first 100 days: in cartoons Mr Trump dropped the "mother of all bombs" on alleged ISIS-linked militants in Afghanistan, amid an escalation of US military intervention around the globe Donald Trump's first 100 days: in cartoons Mr Trump has been accused of falling short of the standards set by his predecessors in the Oval Office, including Franklin D Roosevelt Donald Trump's first 100 days: in cartoons The tycoon's ascension to the White House came at a time when the balance of power is shifting away from Western nations like those in the G7 group Donald Trump's first 100 days: in cartoons Western politicians, including the British Conservative party, have been accused of falling in line behind Mr Trump's proposals Donald Trump's first 100 days: in cartoons Brexit is seen to have weakened Britain, reducing still further any political will to resist American leadership Donald Trump's first 100 days: in cartoons Mr Trump's leadership has been marked by sudden and unexpected shifts in global policy Donald Trump's first 100 days: in cartoons Trump's controversial missile strike on Syria, which killed several citizens, was seen by some analysts as an attempt to distract from his policy elsewhere Donald Trump's first 100 days: in cartoons The President has also spent a large majority of his weekends golfing, rather than attending to matters of state Donald Trump's first 100 days: in cartoons Though free of gaffes, a visit from Chinese president Xi Jinping spotlighted trade tensions between the two states Donald Trump's first 100 days: in cartoons One major and unexpected setback came when Mr Trump's Healthcare Bill was struck down by members of his own party Donald Trump's first 100 days: in cartoons Mr Trump has been a figure of fun in the media, with his approval at record lows Donald Trump's first 100 days: in cartoons A string of revelations about Mr Trump's financial indiscretions did not mar his surge to the White House Donald Trump's first 100 days: in cartoons Outgoing President Barack Obama was accused of wiretapping Trump Tower by his successor in America's highest office Donald Trump's first 100 days: in cartoons The alleged involvement of Russian intelligence operatives in securing Mr Trump the presidency prompted harsh criticism Donald Trump's first 100 days: in cartoons The explosive resignation of Security Adviser Michael Flynn, who lied about his links to 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a federal justice, the President mocked the 69-year-old as a "ridiculous", "so-called judge" Donald Trump's first 100 days: in cartoons A week after his inauguration, Theresa May met with Mr Trump at the White House Donald Trump's first 100 days: in cartoons Donald Trump's first days in office were marked by a hasty attempt to follow through on many of his campaign promises, including the so-called Muslim ban Donald Trump's first 100 days: in cartoons Donald Trump's decision to ban citizens of many majority-Muslim countries from the US sparked mass protests Donald Trump's first 100 days: in cartoons Revelations about Donald Trump's sexual improprieties were not enough to keep him from being elected President Donald Trump's first 100 days: in cartoons British PM Theresa May was criticised by many in the press for cosying up to the new President Donald Trump's first 100 days: in cartoons One of Mr Trump's top aides, Kelly Anne Conway, was mocked for describing mistruths as "alternative 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Scott Horton, a lawyer specialising in anti-corruption cases with experience of the former Soviet Union and knowledge of the Republican party leadership, points out that attempts to kill off the investigations by the Trump team have, so far, failed.

He recently said: “The Republicans have decided that the game of stalling the investigations entirely, as Nunes had tried to do, was backfiring in a big way, and that they were taking a drubbing in opinion polls where there has been a steady shift to calling for an independent commission, which is the worst outcome for them. They want to have some control.”

However, he also believed that the Congressional inquiries still lacked sufficient staff to carry out a proper investigation. In particular, he felt, they needed experts in forensic accounting with an understanding of post-Soviet financial practices, and techniques used by oligarchs to mask asset transfers.

But Mr Horton saw an obvious solution: “There are a lot of FBI agents with this kind of expertise. They should not be hard to find.”