Public relations officer Laura Milburn (Lizzy McInnerny) was introduced as a love interest for Ash, with their romance culminating in a wedding during the series finale.

Robinson reprised the role for the two-part series 12 finale in 1998, with Ash acting as best man at Charlie Fairhead's (Derek Thompson) wedding.

The character's reintroduction was announced in 2013, fifteen years since his last appearance; he returns in the series twenty-seven episode "If Not for You", originally broadcast on 9 February 2013.

Producers used the characters of Ash and junior doctor Lily Chao (Crystal Yu) to explore workplace bullying.

The character was written out of the show off-screen in 2015, making his final appearance in the series 29 episode "Solomon's Song", originally broadcast on 13 December 2014.

Robinson was cast in the role of nurse Martin "Ash" Ashford in 1990 after touring Africa with the Royal Shakespeare Company.

Ken Hodges (Christopher Guard) was given the position, which "niggled" Ash as his friend Charlie Fairhead (Derek Thompson) was on the decision panel.

[18] Kingsley noted that although Ash began the series happy in his new role with added administration responsibility, this changed after he is involved in a racist attack.

[20] In an interview with Evening Standard's Jim Thorpe, Robinson observed that "racism, in one form or another, is everywhere", including on the Casualty set.

[19] Nurse Jude Korcanik (Lisa Coleman) criticises Matt and when he witnesses another incident of domestic violence at home, he agrees to testify in court.

In the narrative, Ash begins to feel uneasy following his return and decides to take a lecturing job at the local nursing college.

[21] Robinson told Caroline Sutton of the Sunday Mirror that he regularly informed scriptwriters about how his character would talk, which sometimes created arguments.

[21] Producers did not agree with Robinson's idea for a black love interest and instead cast white actress Lizzy McInnerny in the role of "posh and pretty" public relations officer Laura Milburn.

[28] Robinson had suggested introducing the character's father, but had to lead rewrites for the stories due to "subtle racism" in the original scripts.

[27] In July 1995, Robinson told Anton Antonowicz from the Daily Mirror that he did not want to remain with the series forever and would leave in the near future.

[29] Reflecting on his time on the show, Robinson said it was "a huge learning experience", which helped him to support his family and become known in the acting industry.

[32] He returns alongside former cast members Shipton (Duffy), Mantle (Clive) and Brenda Fricker (Megan Roach), who all signed a £10,000 contract to appear in the finale.

[32] A Daily Record columnist reported that producers believed they had "pulled off a coup" by securing the four returns as part of "nail-biter" finale.

[33] Ash returns to act as the best man at Charlie's wedding to Baz Wilder (Julia Watson), but is thrown into helping the team when an accident occurs.

[35] Robinson revealed in a 2012 interview with the Sunday Mercury that he had previously been approached to reprise the role again, but he could not due to prior commitments with the Royal Shakespeare Company.

[37] Johnathan Young, the show's executive producer, expressed his joy at Robinson's return and deemed him "a hugely popular character".

Arriving late for his shift, he is then left in charge of the ED when clinical lead Zoe Hanna (Sunetra Sarker) becomes unwell.

[39] Jonathan Phillips, a show producer, told a Penarth Times reporter that the characters would be involved in a "dramatic, turbulent and exciting" story.

Robinson told Elaine Reilly from What to Watch that his character decides that Ella needs to "learn the hard way" in order to change and gives her "a really sharp, serious shock".

[45] Ash works with paramedic Jeff Collier (Matt Bardock) to save the boy and they both jump into the "ice-cold dock with no thought for their own safety".

[46] Back in the ED, Lily praises Ash for his work at the dock but he is furious that a junior doctor would appraise him and verbally abuses her.

"[46] They told Sarah Ellis of Inside Soap that Ash is appalled to have to justify his decisions to Lily, who is "mortified to be given such a public dressing-down".

[47] Elaine Reilly from What to Watch pointed out that Ash "expresses genuine remorse for the heartache he caused his junior doctor".

[48] Robinson was written out of the show in 2014, making his last appearance in the series 29 episode "Solomon's Song", originally broadcast on 13 December 2014.

[51] "Standing strong and silent on the wards of Holby General, Charge Nurse Martin Ashford copes with the dramas of day-to-day hospital life like a true pro!