Thousands of farmers are set to protest outside the Welsh Government amid unrest at policies including the Sustainable Farming Scheme (SFS).
Farmers Guardian has been told more than 10,000 people are expected to arrive at the Senedd on Wednesday (February 28) to protest against the SFS - which proposes to take agricultural land out of production for tree planting and wildlife habitat creation among its priorities.
Concerned farmers have said the scheme could have an impact on their livelihoods with thousands of jobs lost and the impact it could have on the Welsh economy.
The Welsh Government has said the scheme could affect 5,500 farming jobs.
South Wales Police said they have been made aware of a planned protest being held in Cardiff Bay at around 12.30pm.
Farmers protest outside office of Rural Affairs Minister Lesley Griffiths in Wales
Officers said the protest is expected to attract a large number of people, along with some slow-moving traffic on routes to Cardiff Bay and the wider South Wales road network.
A police operation will be in effect for the duration of the protest with controlled access to some roads around the Senedd.
Police officers have asked farmers not to bring tractors to the protest to ensure the movement of the emergency services is not 'restricted' in a busy city centre.
Superintendent Esyr Jones said: "South Wales Police respects the right to peaceful protest and we are in discussions with the organisers to ensure that the protest takes place safely, lawfully with minimum disruption to the wider public.
Farmers asked to donate old wellies for Senedd display to highlight SFS impact
"While there is an agreement to facilitate protest activity outside the Senedd, I would urge protestors not to bring tractors or other agricultural vehicles to the protest.
"There are concerns that they pose a risk to the safety of other road users and restrict the movement of emergency services in a busy city environment.
"We will monitor the situation across the day and motorists should check for any disruption on the road network and plan their journeys accordingly.
"We will advise the public of any delays or disruption throughout the course of the day."
Welsh farmers protest in Rhyl as First Minister Mark Drakeford visits the town