Scotland's farming union has called for immediate action to secure the future of migrant seasonal agricultural workers in the lead up to Brexit and beyond.
MPs on the Scottish Affairs Committee were told the issue is already impacting on farmers north of the border, with high-value crops left to rot in fields due to a lack of labour.
Jonnie Hall of NFU (National Farmers Union) Scotland said the availability of workers for seasonal jobs such as fruit and vegetable picking was already waning as the UK prepares to leave the EU.
The end of freedom of movement of workers after Brexit will make the retention of such workers even harder, he added.
Mr Hall said the NFU believed the UK Government "needs to come out with a very clear statement very very soon indeed about certainly addressing Labour issues for 2018", adding that "we have experience of our members who have got very very high value crops in the field that have simply rotted over the winter because there hasn't been the labour to pick the vegetables".
The union is calling on the UK government to bring forward a new version of the Seasonal Agricultural Workers Scheme (SAWS).
The scheme was originally introduced to allow fruit and vegetable growers to employ migrant workers from Bulgaria and Romania as seasonal workers for up to six months at a time ahead of the lifting of EU restrictions on nationals from those countries.
Mr Hall said: "We think it is incredibly low-hanging fruit for the Home Office just to simply take that (SAWS) off the shelf and revise it quite easily, and that would address very quickly the requirement for seasonal workers.
"And that requirement is here and now.
"We think at any one time in Scotland there are between 5,000 and 15,000 seasonal agricultural workers picking fruit, picking veg and so on, earning significant amounts of money and contributing enormously to the rural economy.
"We think that we need to secure their future as soon as possible, and we think that the SAWS scheme or a vision of the SAWS scheme is the easiest thing to do."