Trade Union Unite said its switchboards were "on meltdown", with calls "every 12 seconds", since it called on former Focus staff to get in touch and see if they are eligible for compensation.
Following the ruling against Focus at a recent employment tribunal, which found the collapsed retailer had breached employment law and saw axed staff awarded 90 days' pay, Unite has been swamped with calls about compensation claims.
The trade union, which brought the case against Focus, offered to put in claims for those staff who qualify, even if they are not Unite members, and have asked staff to get in touch to see if they qualify.
Unite's Caroline Crolley explained that employees who were working at a Focus store employing 20 or more staff as at May 19, before store closures started in June, would be eligible for a payout.
To date, Unite has been in talks with around 1,200 former Focus employees.
Ms Crolley told DIY Week: "Our switchboard has been on meltdown. At one point we had two people manning it and we were getting calls every 12 seconds."
She added: "We worked out that there were potentially 2,000 employees in the stores and we expected 50% of those to be able to claim compensation, so it could be around 1,000 people who will qualify."
According to Ms Crolley, it isn't just retail staff who stand to receive compensation from Focus, as more than 100 of the DIY chain's former head office staff have also won their case against the firm.
Unite regional officer Ms Crolley explained that administrators Ernst & Young, who handled the case, weren't liable for the breach of employment law, adding that it was down to Focus to consult with staff as soon as it knew it was struggling. "When they knew they were in difficulty, that's when they should have started consulting," she said.
She told DIY Week that she had been surprised to learn of the administration, as the firm had given no indications in conversations leading up to the event. "I had arranged pay talks with them the week before and they had been saying that they thought they could afford to stretch to an increase above the minimum wage," she said. "The next thing, I have to hear from the press that they've gone into administration. That's how bad it was."