In a letter sent on Wednesday, Teagasc warned around 1,700 farmers that they could miss out on months of GLAS payments because of the backlog in setting them up on the department's website.

"For various reasons your application was in the last 20% of applicants to be set up on the Department of Agriculture, Food and the Marine's planning system and because of this, it may not be possible to process your application before the closing date of May 22nd for Tranche 1," the letter reads.

Teagasc's head of advisory services Dermot McCarthy, who signed the letter, told the Irish Farmers Journal that of the 11,500 who requested assistance from Teagasc and its partner Farm Relief Services (FRS) to plan and register their GLAS application, around 9,500 were expected to go ahead with their application - but only four in five of those would be registered in time with the the department.

"We have been working 100% flat out, but we couldn't overcome the technical glitches in time in terms of setting people up on the department's GLAS system," McCarthy said.

All farmers who received the letter may not miss the deadline - "it depends on the number of dropouts, on how well the computer system works and whether there is an extension," McCarthy added.

Teagasc: deadline should be pushed back

Teagasc has been asking the department to push back the 22 May deadline. The letter sent to farmers states that it would take the agency "another couple of weeks" to register all its clients.

While the Teagasc/FRS GLAS advisory service has been working on a first-come, first-served basis, even early applicants are likely to be among those who miss out on Tranche 1 because the backlog has been building up at the stage when applications are complete and ready to set up on the department's website.

In its letter, Teagasc offers two options to farmers affected by the backlog: either go through a private planner - while warning that they, too, "are having difficulties in completing plans"; or wait until Tranche 2 of GLAS in the autumn, when "Teagasc will give first priority" to those who missed the Tranche 1 deadline.

"We don't expect major changes then - it will essentially be the same scheme," McCarthy said.