The new forms cover a range of farming subsidies

The deadline for the new forms to be completed is 16 May.

But the Farmers' Union of Wales (FUW) said the Welsh Assembly Government's agriculture department sent out the forms too late.

The department accepted there had been problems but said it was working to ensure forms were filled in on time.

The department said there should now be an effort to return the forms on time.

More than 20,000 of the forms, which are for the new single farm payment, have been sent out during the past few weeks.

So far, just 4,500 have been returned to the assembly's agriculture department.

The FUW said not enough time was given for farmers to complete the new form.

'Pressure on'

If the forms are not returned by the 16 May deadline, outstanding claims will not be paid in full.

Arwyn Owen of the FUW said the union was concerned at the lack of time now available to complete the work.

He added: "The pressure is going to be on in the next week to ensure that these forms are returned on time.

"Our concern is that it's going to put huge pressure, not only on our staff, but on assembly staff and there just won't be the resources there to give the farmers who haven't filled out the form the support they need to complete the form.

"That is a very real concern."

Rita Jones from the agriculture department in Carmarthen said: "While we appreciate that we did encounter problems, we are doing our utmost to work with the farming unions and with all farmers in Wales to make sure that they get these forms in on time.

"We don't want anybody to lose out on their entitlements and on their payment for future years."