Eva Longoria says Gabrielle Union's 'America's Got Talent' firing is ''unacceptable''.

The 44-year-old actress took to Twitter to thank Union, 47, for ''speaking up about toxic culture'' at the NBC show following reports she had complained about racial bias and discrimination.

She tweeted: ''Thank you @itsgabrielleu for speaking up about the toxic culture at @NBC's #AmericasGotTalent. It's time for NBC to take these allegations seriously. Join me & @TIMESUPNOW in calling for accountability & concrete action from @NBCUniversal leadership.

''What @gabunion experienced on set at @NBC's #AmericasGotTalent is unacceptable. It's time for @NBCUniversal to commit to long term, concrete action to fix its toxic workplace culture and ensure safety and equity for all its workers.''

She also tweeted a link to a Time's Up petition defending Gabrielle, with the title 'Stand with Gabrielle Union and Demand Accountability from NBC'.

The petition states: ''For too long, NBCUniversal has enabled toxic workplaces by protecting the careers of powerful men like Matt Lauer at the expense of women who speak out and are silenced through non-disclosure agreements.

''Now, Gabrielle Union was allegedly fired for speaking up about racist and inappropriate behaviour she encountered working on NBC's 'America's Got Talent'. Union reportedly endured and witnessed racially-insensitive comments and excessive criticism about her physical appearance, and it also appears she was punished for speaking out.

''It's time for NBC to stop protecting powerful men at the expense of its workers and address its toxic workplace culture, once and for all.

''TIME'S UP applauds Union for her courage and once again calls on NBC to take these allegations seriously and take concrete steps to foster a safe and equitable workplace. Union's experience shows that NBCUniversal still has a lot of work to do to change its culture, so discrimination, harassment, and retaliation are no longer tolerated at the company.''

Meanwhile, Gabrielle is set to meet with NBC this week to discuss her departure from 'America's Got Talent'.

The actress will sit with the outside legal team recently retained by the network to talk about her concerns over the ''toxicity'' surrounding the show.

The purpose of the meeting is to improve the culture and atmosphere on the set of the show and even if she's offered her job back, Gabrielle won't be returning.

A source told Deadline: ''Gabrielle believes there is a toxicity that has become normalised at Talent.

''She wants to help fix that, because she loved a lot of her time on the show last season, even with the issues with Simon [Cowell] and what have you.

''But she could never go back, even if they did a [180] and asked her to for another season - no.''