All parties should make an election pledge to improve teaching and learning of modern languages in the UK, a cross-party group of MPs and peers has said.
The All-Party Parliamentary Group on modern languages wants to see a "national recovery programme" to improve language skills.
It claims the UK is already losing £50bn a year over poor language skills.
But the government said its reforms were "driving a languages revival" in schools.
The APPG has been gathering evidence on the impact of poor language skills on the UK economy and its standing in the world.
It suggests businesses are struggling to fill posts and are losing out on export opportunities.
The group has put together its own manifesto for languages - which it has already presented to the main party leaders, and which it is due to publish on Monday.
Baroness Coussins, chairman of the APPG, said: "The next government will need to take clear, urgent and coherent action to upgrade the UK's foreign language skills.
"Otherwise our young people will continue to fall behind their European and global peers in education and employability; our export growth will be stunted; our international reputation will suffer and our security, defence and diplomacy needs will be compromised.
"The UK economy is already losing around £50bn a year in lost contracts because of a lack of language skills in the workforce.
"And we aren't just talking about high-flyers: in 2011 over 27% of admin and clerical jobs went unfilled because of the languages deficit."
She added: "We're looking for an acknowledgement of this issue in all the parties' manifestos for the next general election, backed up by some specific policy commitments.
"The All-Party Group's Languages manifesto provides a good template and the political parties are all welcome to lift it."
The call comes shortly after university application figures revealed a 5% drop in language candidates.
And 2012 European Commission research revealed 9% of 15-year-olds are competent in their first foreign language in the UK, compared with 42% in 14 other European countries.
The Department for Education said £350,000 was being spent in England in the next year to help primary and secondary teachers improve their teaching of languages.
A spokesman added: "We are making it compulsory for children to learn a foreign language from age seven to 14, a move supported by 91% of respondents to our consultation on languages in primary schools.
"Our EBacc means thousands more pupils are now studying languages at secondary school - almost half of state-school pupils entered languages at GCSE last year, the highest level for seven years."