He claims he was forced to leave because handling beer, spirits and wine is against his strict Islamic beliefs and that he was victimised when he asked the company to give him another role.
Ahmed, who was raised in Saudi Arabia, told the tribunal he had no idea his job entailed handling alcohol when he started work at the distribution depot in Lichfield, Staffordshire, last September.
When he realised it did, he asked to be found different work but alleges that one of his supervisors told him: 'You do the job or go home.'
Ahmed also claimed his line manager was 'aggressive' towards him and another supervisor was abusive.
The situation allegedly worsened in November and December when extra alcohol arrived at the warehouse in readiness of Christmas, the tribunal in Birmingham heard.
Ahmed claimed he eventually lodged an official grievance with the company in February but was 'victimised and harassed' as a result.
Asked why he took so long to raise a grievance in the first place, he said: 'Many meetings were being held in the meantime to discuss the situation.'
The tribunal heard that since the case emerged Tesco has ensured its induction process makes clear that handling alcohol is part of the job.
But Laura Canham, the company's solicitor, said it was still unrealistic for Ahmed to say he had no idea what his duties would be.
Ahmed claimed he had never visited a Tesco store and was not aware the company sold alcohol.
But he admitted having shopped in other supermarkets - including Sainsbury's, Lidl and ASDA - and noticing alcohol was on sale there.
Canham said: 'He was advised at the outset what the job would entail. At no stage did he raise the fact he could not handle alcohol.'
She told the hearing managers did all they could to help Ahmed, adding: 'They went to see if there were any other roles available for him.
'He applied for a maintenance job, but he was unsuccessful. All other roles, in some form or other, also came into contact with alcohol.'
Canham denied the company discriminated against him and said: 'It would be reasonable to expect him to be aware of what Tesco did.'
Ahmed, of Derby, who is suing the firm for racial discrimination, victimisation and harassment, is set to learn the outcome of the case later this week, Daily Mail reports.
He said: 'I was asking for my rights. I am not saying I am a perfect person, but there was a conflict with my beliefs.
'It is in our religion that we are not allowed to handle alcohol. In the UK there are equal opportunities that should protect me and my beliefs.'
Saudi Arabia's enforcement of strict Sharia law regarding alcohol is among the harshest in the world.
Sentences include several months' imprisonment for simply drinking beer, and it is not unknown for offenders to be given lashes as well.
A spokesman for Tesco, whose Ģ63 million Lichfield depot employs around 1,000 people, said: 'Cases like this are very rare.
'Managers are trained to be culturally sensitive and have an "open-door policy" to staff for issues like this, as everyone is welcome to work at Tesco.'