Former footballer Ryan Giggs admitted Tuesday to being unfaithful in all his past romantic relationships but denied ever being violent towards partners, as he gave evidence over charges of assault and coercive control of an ex-girlfriend.

Taking the stand for the first time in his week-old trial, the Manchester United legend denied physically assaulting former partner, PR agent Kate Greville, nearly two years ago or controlling her during their rocky years-long relationship.

But under questioning from his own lawyer, the 48-year-old admitted to a lifetime of infidelity, agreeing that he was "a flirt by nature" and unable to "resist" pursuing attractive women despite being married or in a relationship.

Giggs is on trial at Manchester Crown Court over claims he subjected 36-year-old Greville to a "litany of abuse, both physical and psychological" which included headbutting her in the face as she tried to end their relationship.

The former coach of the Wales national team, whose career has been upended by the charges, faces a five-year jail term if convicted.

As the prosecution rested its case Tuesday morning, jurors heard details from a hand-written prepared statement he gave to police after he was arrested on suspicion of assaulting Greville and her sister, Emma, in November 2020.

In it, he described a tussle between the trio over a mobile phone during which Giggs said he "may have caught her and her sister".

"But at no time was there any attempt to harm either of them," the statement added.

Giggs said the pair's more than four-year relationship -- which began while he was married to the mother of his two children -- had its "ups and downs".

"Despite allegations of violence, I often walk away from incidents," the former footballer insisted in the police statement, adding: "I would never react with violence".

He also told officers in another later statement, which was also read in court: "I will not accept that my behaviour towards my former partner has been in any way controlling or coercive".

During several hours of afternoon testimony from the witness box which charted the course of their "rollercoaster-type relationship", Giggs denied threatening to release certain images or video of Greville in a bid to emotionally blackmail her.

He told the court he had "never" shared any private photos or videos, insisting that he would never share such material.

The trial continues Wednesday.

A dazzling teenage talent, Giggs ended his career at Old Trafford as the most-decorated player in English football history.

As a player, he made a club-record 963 appearances over 23 years for Manchester United, winning 13 Premier League titles and two Champions League trophies.

He then began his coaching career at Old Trafford, taking temporary charge at the end of the 2013/14 season after David Moyes was sacked, before working as an assistant to Louis van Gaal for two years.

Giggs was appointed Wales boss in January 2018 and helped them secure qualification for Euro 2020, just their second major tournament appearance since the 1958 World Cup.