Farmers in France, the European Union's biggest agricultural producer, complain they face unfair competition from rivals due to varying environmental standards among EU states.
To press their demands for the French government do more to help them weather inflation and compete with cheap imports, French farmers have set up roadblocks on major roads over the last week.
On Monday, tractors blocked major highways near Paris and across France as the protests intensified, causing headaches for the 20,000 Spanish trucks that cross into France daily.
"The production and marketing rules in the EU are similar in all member states and we all apply them in the same way," Planas told reporters on Monday.
"There is no competitive advantage derived from the application of different rules."
French Prime Minister Gabriel Attal said on Sunday his government was considering further help for farmers "regarding those aspects of unfair competition", without mentioning Spain specifically.
With French blockades causing delays in exporting Spanish produce - including fruit, vegetables, meat, olive oil and wine - to the north, some exporters have started to use short shipping routes, Spanish retail and food industry association Aecoc said.
"Traffic is increasing in the ports of Santander and Bilbao, which have short sea shipping routes to the U.K. and from Barcelona and Valencia, the start of the 'maritime motorway' to Italy," it said.
Spain's federation of transport associations, Fenadismer, said the UK export market accounted for just 7% of Spanish exports and shipping was not an alternative for most exports going to Europe.
(Reporting by Emma Pinedo and Corina Pons. Additional reporting by Bertrand Boucey in Paris, editing by Aislinn Laing and Ros Russell)
