Donald Trump’s determined efforts to seize and wield ever greater power within government are setting more alarm bells ringing as opponents claim the president has now engineered significant legal sway within the Department of Justice.

Attorney General William Barr is increasingly taking control of “legal matters of personal interest to President Donald Trump”, NBC News reports, citing “multiple people” familiar with the matter.

The move has been widely interpreted as an erosion of the separation of powers between the president’s office and the justice system — a keystone of democracy.

Concerns have mounted after Mr Barr apparently intervened in the Roger Stone case.

Last year Stone was convicted on seven counts, including witness tampering and lying to investigators in relation to his work for the Trump campaign.

Donald Trump celebrity president: A decade in two halves Show all 29 1 /29 Donald Trump celebrity president: A decade in two halves Donald Trump celebrity president: A decade in two halves Trump styles his 'You're fired!' pose in his Trump Tower office in June 2012. At the time he was known as a reality TV star on The Apprentice Diane Bondareff/Invision/AP Donald Trump celebrity president: A decade in two halves He was also well known as the patron of the Miss Universe competition Getty Donald Trump celebrity president: A decade in two halves Early signs of Trump's ambition for the presidency can be found everywhere. Not least in his 2011 book 'Time to get tough: Making America #1 again' Getty Donald Trump celebrity president: A decade in two halves Trump with Piers Morgan in November 2010. Piers Morgan has long held that he and Trump are good friends Getty Donald Trump celebrity president: A decade in two halves Trump appeared on Fox & Friends, his favourite show, in August 2011 Getty Donald Trump celebrity president: A decade in two halves Trump considered running in the 2012 election, where he would have faced Barack Obama. He is speaking here at an event for a Republican women's group Getty Donald Trump celebrity president: A decade in two halves Trump was subject to a Comedy Central roast in 2011. He is pictured here being roasted by rapper Snoop Dogg Getty Donald Trump celebrity president: A decade in two halves Given that this Trump store is in the lobby of Trump Tower, it can be said that Trump sells merchandise of himself out of his own home Getty Donald Trump celebrity president: A decade in two halves Trump held meetings with prominent Republicans when considering his 2012 bid. He is pictured here with Alaska governor Sarah Palin Getty Donald Trump celebrity president: A decade in two halves He didn't end up running in 2012 afterall, instead endorsing Republican candidate Mitt Romney AFP/Getty Donald Trump celebrity president: A decade in two halves Trump's golf course in Aberdeen proved controversial in 2012 when he began lobbying the Scottish government against wind power in order that they wouldn't install turbines off the shore by his new course Getty Donald Trump celebrity president: A decade in two halves He even gave evidence to a Scottish parliamentary committee discouraging wind energy AFP/Getty Donald Trump celebrity president: A decade in two halves He still found time for a round of course AFP/Getty Donald Trump celebrity president: A decade in two halves On 16 June 2015, Trump announced that he would run for the presidency of the United States in the 2016 election as a Republican Getty Donald Trump celebrity president: A decade in two halves His campaign was divisive, courting controversy wherever he went. Ultimately he was declared the Republican candidate in June 2016 Getty Donald Trump celebrity president: A decade in two halves Trump took part in the TV debate against opponent Hillary Clinton on 9 October Getty Donald Trump celebrity president: A decade in two halves Trump and wife Melania vote in the presidential election on 8 November 2016 AFP/Getty Donald Trump celebrity president: A decade in two halves Hillary Clinton conceded defeat at 2:50am on 9 November and president-elect Trump swiftly delivered his victory speech to a crowd of supporters Getty Donald Trump celebrity president: A decade in two halves News coverage around the world focused on the huge political upset that Trump's victory spelled AFP/Getty Donald Trump celebrity president: A decade in two halves Trump met with president Obama to discusss transition planning on 10 November. AFP/Getty Donald Trump celebrity president: A decade in two halves Donald Trump and Nigel Farage pose in the golden elevator at Trump Tower on 12 November 2016. Farage was the first British politician to meet with Trump after the election LeaveEUOffical/Twitter Donald Trump celebrity president: A decade in two halves The inauguration of Donald Trump took place on 20 January 2017. Trump's press secretary Sean Spicer boasted that the crowd was the 'largest ever' to witness an inauguration, a claim that was proved not to be true Getty Donald Trump celebrity president: A decade in two halves In his first 100 days as leader, Trump signed 24 executve orders, the most of any president AFP/Getty Donald Trump celebrity president: A decade in two halves One of Trump's most memorable election pledges was to build a wall between the US and Mexico. He is standing here in front of a prototype for a section of the wall Getty Donald Trump celebrity president: A decade in two halves Trump's meetings with other world leaders have provided no short supply of photo opportunities Getty Donald Trump celebrity president: A decade in two halves Trump was welcomed to the UK by the Queen and a state banquet was held at Buckingham Palace in his honour Reuters Donald Trump celebrity president: A decade in two halves Not everyone welcomed the president. Mass protests were held in London throughout his visits in both 2018 and 2019 EPA Donald Trump celebrity president: A decade in two halves One of the most significant meetings Trump has held with another leader was with North Korea's Kim Jong Un. In June 2019, Trump became the first sitting president to set foot in North Korea Getty Donald Trump celebrity president: A decade in two halves 2020 will see president Trump fight for a second term in office, who knows what the next decade will bring? Getty

But on Tuesday, the president lashed out at the sentence recommended by Stone’s prosecutors, of nine years in jail.

“This is a horrible and very unfair situation. The real crimes were on the other side, as nothing happens to them. Cannot allow this miscarriage of justice!” Mr Trump wrote on Twitter.

His tweet was condemned by Democrat House speaker Nancy Pelosi, who said the president had “engaged in political interference in the sentencing of Roger Stone”, and said his actions should be investigated.

Later on Tuesday, the prosecution team then resigned en mass, when the Department of Justice — reportedly under Mr Barr’s direction — said it was planning to reduce the recommended sentence.

Mr Trump’s administration has also rescinded the nomination of Jessie Liu, who had supervised the Stone Case, for a job as an undersecretary at the Treasury Department.

Ms Liu was also overseeing the inconclusive criminal investigation into former acting FBI director Andrew McCabe, who was accused by the Department of Justice’s inspector general of lying to investigators. Mr McCabe has not been charged, despite Mr Trump repeatedly saying he should be sent to prison.

Mr Trump and Mr Barr’s interventions in the Department of Justice come as the president has attacked those officials subpoenaed to testify in the impeachment proceedings against him.

Democrat politician and Senate minority leader Chuck Schumer, has called on the Justice Department Inspector General to “open an investigation immediately”.

“The president seems to think the entire Justice Department is just his personal lawsuit to prosecute his enemies and help his friends. Rule of law in this grand tradition in this wonderful Justice Department is just being totally perverted to [suit] Donald Trump’s own personal desires and needs, and it’s a disgrace,” Mr Schumer told reporters in Washington.

Dr Brian Klaas, a UCL lecturer and expert on democracy, authoritarianism and American politics, told The Independent Mr Trump and Mr Barr were in “serious breach of democratic norms”.

He said: “For a country to be a democracy, rule of law must be completely separate from political machinations. In authoritarian regimes — and in countries lurching towards authoritarianism like Turkey or Hungary — rule of law is a weapon wielded by the leader. They use it to protect their political allies and investigate their political rivals.

“With Attorney General Barr, President Trump has found someone willing to bend rule of law to his whims and wishes. And what’s remarkable is that it’s not even being done secretly. Trump is openly calling to investigate political rivals. He has repeatedly called to imprison political opponents. And now the Justice Department, which is supposed to be separate from politics, is getting directly involved in a case to reduce the sentence for the president’s longtime friend and adviser, Roger Stone.