Secret Service officer Gary Byrne was walking back to the White House’s West Wing one Christmas when he and a Secret Service colleague ran into a White House steward.

He was just pushing open the door of the Map Room and, expecting to find it empty at that time of night, didn’t bother to knock first. That was a big mistake.

Byrne says that inside the Chippendale-style parlour room where Franklin Roosevelt had guided America’s entry into World War II, he was stunned as he caught sight of President Bill Clinton in a ‘compromising position . . . that is, making out on the Map Room table’ with a glamorous young blonde TV presenter.

The girl was Eleanor Mondale, daughter of the former Vice-President Walter Mondale — though the pair were clearly not discussing politics.

Eleanor Mondale, the daughter of former US Vice President Walter Mondale, who is alleged to have had a relationship with former US President Bill Clinton

The steward quickly shut the door and the three witnesses hurried away. No more was said. But, as Byrne alleges in a new memoir causing major ructions in the U.S., White House staff were expected to ignore — or even cover up — a shocking amount of ugly behaviour during the Clintons’ eight years in power from 1993 to 2001.

Byrne, whose Clinton era duties included three years stationed directly outside the Oval Office, was the first Secret Service member to formally raise concerns about Monica Lewinsky’s easy access to the President.

Now he has raised different worries. In a scathing portrait of a chronically womanising President and a First Lady with a volcanic temper and an alarming unpredictability, he claims Hillary Clinton ‘lacks the integrity and temperament’ to become President 15 years after her husband left the job.

The new book detailing the allegations against former US President Bill Clinton is expected to cause headaches for wife Hillary's own bid for the White House against Donald Trump

Hurled vases, Presidential black eyes, bodyguards driven to drink and drugs by the nightmare of working for the dictatorial Mrs Clinton and a President who would pick up women on his daily jogs — it’s all here in Byrne’s new book, Crisis Of Character, or in interviews that the author has given to promote it.

As she strives for a historic election victory in November, Mrs Clinton has had to contend with a string of revelations that have raked up the more tawdry details of the power couple’s first stint in the White House.

But Byrne’s What-the-Butler-Saw style account is particularly damning. Of course, he may be a fibber, looking for a chance to cash in with exaggerated anecdotes — but so much of his testimony rings true based on what the world knows about goings-on at the Clinton White House.

It is little wonder the Clinton camp has not only denounced the book, but has even reportedly persuaded most of the big TV news networks to deny Byrne airtime. Undoubtedly to the couple’s horror, Crisis Of Character shot to the top of the Amazon best-seller list from pre-orders alone.

Unsurprisingly, the book’s sensational, gossipy — and hotly disputed — revelations are already being exploited by presidential rival Donald Trump and other Republicans.

Critics have questioned Byrne’s motives and some of his allegations, and accuse him of bringing the supposedly non-partisan Secret Service — whose main role is to protect the President — into disrepute.

Byrne, now retired, counters that it is his ‘patriotic duty’ to ensure voters know the unvarnished truth about the Clintons.

Condemning her ‘appalling leadership style’, he portrays the presumptive 2016 Democrat presidential nominee as ‘volcanic, impulsive, enabled by sycophants, and disdainful of the rules set for everyone else’.

He warns: ‘We all remember — or should remember — what a Clinton White House was like. If we board that time-machine for a return trip — it’s our fault.’

Byrne insists that, stationed feet away from the President, he never needed to listen at keyholes. Mrs Clinton, he says, screamed at top volume through a White House so badly sound-proofed that conversations in any room were easily heard in the hallways outside.

Former White House staffer Monica Lewinsky's affair with Clinton rocked the White House in the late 1990s

From the moment they moved into the White House in January 1993, Mrs Clinton made clear she was going to be a far more politically active First Lady than her predecessors, becoming the first to set up an office near the President in the West Wing.

Staff, and particularly the Secret Service who Mrs Clinton reportedly loathed and saw as the liberal couple’s dyed-in-the-wool conservative enemy, quickly learned to give her a wide berth.

To force the message home, Mrs Clinton made it plain she expected staff to keep out of her way as she marched through the White House. She allegedly liked to make life hard for her bodyguards by charging outside for impromptu jogs.

Byrne claims that she once threw a Bible at a Secret Service agent on her protection team, hitting him squarely in the back of the head.

While he rarely saw Mr Clinton get angry, Byrne says the First Lady was over-indulged by ‘doting, barely post-adolescent’ staff and was prone to ‘massive tantrums’. Some agents ‘literally went mad’ from the stress of protecting her, he claims, turning to alcohol, drugs, office affairs and even prostitutes.

‘I always avoided eye contact when she was on the warpath,’ he says. She would ‘explode in my face without reservation or decorum’, he recalls.

Presumptive Democratic presidential nominee Hillary Clinton attends a town hall with about 100 millennials, who are digital content creators and social media experts, last month. The new claims against her husband could cause her campaign some headaches

However, when talking to a visiting VIP, she’d put her hand chummily on Byrne’s shoulder and say: ‘This is one of my favourite officers, Gary Byrne.’

Hillary reserved her worst screaming fits for her husband, he says. While Byrne admits he was charmed by the friendly, gregarious Bill, his wife was his complete opposite — cold and socially awkward.

This contrast was carefully concealed in public but, when surrounded only by underlings, the Clintons didn’t bother to hide the uncomfortable relationship they had, says Byrne.

As was confirmed at the 1998 grand jury inquiry into the Monica Lewinsky scandal, Byrne was one of the first to become concerned about Mr Clinton’s strange relationship with the bubbly and buxom intern.

Lewinsky was, of course, the young woman he would later famously deny having ‘sexual relations’ with.

Byrne — the last barrier between unauthorised visitors and the President — was annoyed at the way Lewinsky wandered around the West Wing in an endless, unsubtle quest to engineer encounters with the President.

‘Monica hung around us batting her eyes until she overheard the President’s position or direction of travel, then bolted to manoeuvre into his path,’ Byrne writes. ‘She lived for even his passing glance.’

According to Byrne, every Secret Service officer discovered Bill and Lewinsky in compromising positions — ‘either unprofessionally close, embracing each other, making out or on the Oval Office desk’ — but were too scared for their careers to speak out about it.

‘It was incredibly awkward to be roped into the President’s cheating,’ says Byrne. ‘Why would a supposedly brilliant Rhodes scholar like Bill Clinton embark on such risks?’

Lewinsky frequently wore overly short dresses to attract presidential attention, he says. Byrne recalls how she once ‘flipped up her black-and-white print dress to reveal her blue thong’ for Mr Clinton, who laughed and ‘said something like: “Hey, there!” ’

Byrne could barely believe it when he discovered Mr Clinton had given Lewinsky his ‘secret number’ — a telephone code to contact him in which four numbers had to be pressed for specific periods of time and with similarly precisely timed pauses between each number.

Days after Byrne complained about Lewinsky hanging round the Oval Office as an intern, she was back, flaunting her new pass as a paid member of White House staff.

The U.S. Navy stewards who served as butlers at the White House were usually the first to discover physical evidence of Clinton’s philandering, says Byrne.

One, who he names as Nel, shared that evidence with Byrne, revealing that over a period of time, he had been finding and secretly cleaning White House embossed towels stained with lipstick.

Anxious to protect the presidency from embarrassment, Nel was washing them by hand rather than sending them to the laundry.

According to Byrne, the lipstick was clearly not the shade worn by Lewinsky or Hillary. He believed it belonged to a young White House receptionist who was also having an affair with Clinton.

Byrne claims he ended up helping Nel to dispose of one of the towels, adding that the stained blue Lewinsky dress which famously proved Clinton’s guilt wasn’t ‘the only evidence of his misdeeds’.

Sexual allegations against former US President Bill Clinton have hounded the family for decades. He is pictured here with Hilllary and daughter Chelsea at Nelson Mandela's 85th birthday party

There were many other women besides Lewinsky, Eleanor Mondale and the unnamed receptionist, says Byrne.

Identifying for the first time something he says was dubbed the ‘jogging list’, he recalls how, early in Clinton’s first administration, women ‘dressed as if they were going clubbing or working out’ would wait by the White House south-east gate for him to take his daily exercise.

His bodyguards would collect their names and carry out security checks on them. ‘Agents . . . insinuated that this list was used by President Clinton to try to meet these women,’ says Byrne.

He recalls an incident in December 1997 when he heard on his two-way radio that Monica Lewinsky was at one of the White House gates.

The guard had been instructed to delay her entrance . . . because Mr Clinton was already ensconced with Eleanor Mondale. Suspecting the truth, Lewinsky — according to Byrne — furiously gestured at herself and told the guard: ‘What’s he want with her when he has this?’ (Mondale’s affair with Clinton was strongly rumoured at the time although she denied it. She died of brain cancer in 2011.)

Was Hillary aware of his philandering? Byrne suspects that she knew about some of her husband’s affairs but not Lewinsky, who, at 22, was young enough to be their daughter.

He doesn’t speculate whether it was the cheating that accounted for their furious rows — so physical, Byrne alleges, that Secret Service agents discussed intervening to protect him.

Byrne recalls arriving for work in 1995 after a particularly loud argument between the couple the previous night had ‘ended with a crash’. Staff discovered an antique blue vase had been smashed and Bill had ‘a shiner’ of a black eye.

The account chimes with previous claims that the Clintons fought on at least one occasion over his affair with Lewinsky. Byrne gilds Mrs Clinton’s aggressive image by recounting how — some years later — she and her husband visited the Secret Service’s firing range.

Mrs Clinton chose an old Thompson sub-machine-gun and, ‘smiling ear-to-ear’ let rip, pumping bullets into the male target’s crotch area. Witnesses laughed, looked away in embarrassment or glanced at the President, says Byrne.

Almost as ferocious as the Clintons’ fight related by Byrne is the current battle between the Democrats and Republicans over this explosive book.

And it’s not just historic allegations being thrown around. Even at 69, Mr Clinton’s sex life is still proving controversial, with his charity foundation recently facing questions over a $2 million donation to a company partly owned by a woman alleged to be his mistress.

The Clinton camp has dismissed the memoir as ‘fantasy’ without addressing specific claims. Also, some media supporters have noted that some of Byrne’s claims contradict what he told the 1998 official inquiry that led to Bill Clinton’s impeachment.

(Others argue that Byrne, who clearly likes Mr Clinton much more than his wife, was lying to protect him at the time, but feels no such qualms about damaging Hillary).

Some former Secret Service agents allege Byrne was too low-ranking to see everything he claims, and accuse him of recycling old rumours.

Others, however, have rushed to his defence.

Dan Emmett, a respected former agent and Secret Service historian, says Byrne spent ‘many hundreds of hours’ just feet from the President, adding: ‘He was without question in a position to see and hear at least some of the things he claims.’