The price of British strawberries could rise by 50% if ministers fail to plug growing gaps in seasonal labour which are expected to get worse after Brexit, MPs have heard.

The prospect of a £3 punnet of strawberries was raised by MPs as they called for a new seasonal agricultural workers scheme to be introduced by next year – or sooner – to stop the shortage of EU labour becoming a crisis.

Neil Parish, former chair of the environment, food and rural affairs select committee, who secured a debate on the shortage of labour, said: “There are two points to this debate; to highlight the current problems experienced by many in the horticultural and agricultural sectors in recruiting enough seasonal workers, and to propose a new scheme after Brexit and make sure these industries have enough seasons workers to pick British fruit and veg.

“This country relies on foreign labour to pick its fruit and veg; 80,000 seasonal workers pick and pack it every year. The majority of them are from the EU, mainly from Romania and Bulgaria. Without these workers British fruit and veg will potentially rot in British fields, and that is the last thing we want.”

A combination of the fall in the pound, uncertainty over the status of EU migrants after the Brexit vote and the improving wages in countries like Poland, meant seasonal labour was becoming harder to recruit, Parish said.

Parish, a former chair of the Environment, Food and Rural Affairs select committee, said 78% of respondents to an inquiry into seasonal labour had told the committee recruitment was more difficult this year than last year. A survey by the National Farmers Union in May said there was a shortfall of 1,500 seasonal staff.

“This points to a worrying picture,” said Parish. “In the short term it means some fruit might not be picked and there will be higher prices in the shops. In the long term if British firms struggle to recruit labour they may delay decisions to invest and they could export jobs … abroad. We do not share the government’s confidence that the agricultural sector does not have a problem.

“When Britain leaves the EU in 2019 a new seasonal agricultural workers scheme will become essential.”

A home office minister told the inquiry earlier this year – which was cut short due to the general election – that a seasonal agricultural workers scheme could be introduced in six months if it was deemed necessary. But Parish said he did not have faith that it could be done so quickly.

Pete Wishart, SNP MP for Perth and north Perthshire, said the problem stemmed from Brexit and the desire to end the freedom of movement across the EU. MPs heard that the British summer fruits association predicted prices could rise by up to 50% because of seasonal labour shortages – which would only get worse after Brexit.

Tom Tugendhat, Conservative MP for Tonbridge and Malling, said the seasonal workers picking fruit in Kent were highly skilled and paid well over the national minimum wage. He said: “This is not a low wage economy.”

Minister for agriculture George Eustice, however, told MPs government figures suggested there was no crisis in recruitment of seasonal labour. But he said the situation was being kept under review and was seeking more data from the industry and the NFU. He said the Home Office – which would be responsible for bringing in a seasonal worker scheme – had made clear it could introduce one within six months.