Image copyright Getty Images Image caption Mr Trump reshuffles his campaign staff for the second time in less than two months

With less than three months left until the election, Republican presidential nominee Donald Trump has ordered yet another campaign reshuffle in an effort to revitalise his bid for the White House.

Mr Trump tapped Stephen Bannon, Breitbart News executive chairman, to become his campaign chief executive, and promoted Kellyanne Conway, a senior adviser and pollster, to campaign manager. The additions effectively demoted Paul Manafort - Mr Trump's onetime top campaign aide. He stepped down a few days later.

The transition follows a string of recent controversies and gaffes involving Mr Trump that has left him trailing Democratic rival Hillary Clinton in the polls by an average of about seven percentage points.

The overhaul is Mr Trump's second in less than two months.

Ms Conway confirmed the news early Wednesday, describing it as "an expansion at a busy time in the final stretch of the campaign."

Kellyanne Conway

Campaign manager

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Ms Conway, 49, has served as an adviser and pollster for Mr Trump and his running mate Indiana Governor Mike Pence.

The Republican strategist and veteran pollster first joined Mr Trump's campaign in July after working for a super PAC that supported Mr Trump's primary rival, Senator Ted Cruz.

Ms Conway is considered a gender gap expert who has spent most of her career helping conservative politicians court female voters through her company, The Polling Company/WomanTrend.

Stephen Bannon

Campaign chief executive officer

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Mr Bannon will temporarily step down from his role as executive chairman of Brietbart News, a right-wing political website that has largely favoured Mr Trump, to serve as the Republican nominee's CEO.

He has been criticised for pushing Breitbart's pro-Trump coverage, with former editor-at large Ben Shapiro accusing him of shaping "the company into Trump's personal Pravda."

The former naval officer and investment banker became executive chairman of the company after Andrew Brietbart, the founder of the namesake news network, died in 2012.

Mr Bannon's hiring is considered a return to the "bare-knuckles brawl" politics and populist movement that energised much of Mr Trump's primary run under the leadership of former campaign manager Corey Lewandowski, according to Washington Post's Robert Costa.

A Bloomberg article in October of last year described him as "the most dangerous political operative in America."

Roger Ailes

Informal adviser

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Multiple US media outlets have reported that disgraced former Fox News Chairman Roger Ailes has been tapped to aid Mr Trump as he faces off with Mrs Clinton on the debate stage in September.

Mr Trump has denied the claims, saying Mr Ailes has "no role" in preparing him for the debates.

Before his career at Fox, Mr Ailes was credited with preparing Richard Nixon in 1968, President Ronald Reagan in 1984 and Vice President George HW Bush in 1988 for their debates.

Last month, Mr Ailes stepped down from the network, which he co-founded and ran for two decades, in the wake of allegations that he sexually harassed numerous female employees, including former host Gretchen Carlson and anchor Megyn Kelly.

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Roger Stone

Former campaign adviser

Roger Stone's departure from the primary campaign last August was the first sign of internal conflict simmering within Mr Trump's 2016 bid.

Though Mr Stone, who counts Mr Manafort as a friend and business partner, has no official connection to the campaign, he continues to talk to and advocate for the Republican standard-bearer, according to US media.

Earlier this week, Mr Stone penned an op-ed for the Washington-based newspaper, The Hill, arguing that voter fraud and concerns over electronic voting technology could lead to a rigged election against Mr Trump.

Corey Lewandowski

Former campaign manager

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Mr Lewandowski, now a paid CNN commentator, left the campaign on 20 June but remains in contact with Mr Trump, according to US media.

The 42-year-old, who is considered the brains behind Mr Trump's successful primary run, reportedly had a contentious relationship with several campaign staffers, including then-strategist Mr Manafort.

His brash and abrasive demeanour led to controversy earlier this year, when he was charged with battery after allegedly pulling a female reporter, Michelle Fields, out of Mr Trump's way after an event.

Mr Trump defended his campaign manager until the charges were dropped.

Mr Lewandowski also faced allegations of being sexually inappropriate in tone to female reporters while working on the campaign and in a previous job, according to a Politico report.

Paul Manafort

Former campaign chairman

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Brought on to professionalise Mr Trump's campaign, the 67-year-old seasoned political operative - with help from the Trump children - replaced the combative Mr Lewandowski in June.

However, he struggled to keep Mr Trump on message as the New York real estate mogul's standing in the polls declined.

He advocated a more disciplined, conventional campaign, calling for scripted speeches and teleprompters over Mr Trump's off-the-cuff approach.

Mr Manafort also had come under fire for his ties to Russian oligarchs, foreign governments, and more recently, his work for the Russian-backed, former Ukrainian President Viktor Yanukovych, who fled after an uprising in November 2013.

The New York Times reported in August that the Ukrainian government had discovered ledgers pledging more than $12m (£9.2m) in undisclosed cash payments to Mr Manafort between 2007 and 2012. He has vehemently dismissed the claims.

Mr Manafort resigned on Friday saying he had become "a distraction" to the campaign.