A London-based law firm that has secured grants to set up in NI is offering to pass the money onto staff as an incentive for them to relocate.
Allen and Overy announced plans to move 180 back office jobs from London to Belfast earlier this month.
It has told staff that its aim is "to pass any financial benefits received from the government" to those who take up the offer.
The Ulster Unionist Party said this was not what the grants were intended for.
Invest NI agreed to pay the firm an incentive of about £8,000 in grants for each job it creates.
The firm is offering staff in London first refusal on filling the jobs and if they choose not to relocate they face losing their jobs.
Allen and Overy told staff that, although Belfast was not "the cheapest option", the quality of the city and the government incentives made it a "viable and attractive option".
The Ulster Unionist Party said this offer to pay staff could mean grant money paid out by the Stormont executive is being used to prevent local people filling some of the jobs.
Ulster Unionist finance spokesman David McNarry said: "These are jobs for Northern Ireland people and that is why we are paying the money out of the Northern Ireland purse."
Invest NI defended its system of awarding grants.
The agency's director of international investment Bill Montgomery said companies could use the money "as they see fit" as long as they were "fulfilling the project, employing the people and meeting their targets".
"During the discussions with the company we never mentioned, or talked about any money being used as a direct incentive to relocate," he said.
Economist Philip McDonagh said anyone who did relocate from London would help the Northern Ireland economy because of the multiplier effect attached to their income.
"They bring with them their salary and their spending power," he said.
"They will be looking for accommodation. They will spend their salary, a good bit of it in the local economy, so there is a genuine net contribution to the NI economy."
In addition to the 180 jobs it is relocating from London, Allen and Overy intends to create 317 Belfast jobs over the next three years which would attract a total of £2.5m in grants.
The company, which had a turnover of around a £1bn last year, confirmed it did make the relocation offer to staff. So far, it says it does not know how many people will be taking up its offer.