"A collapse of the future pact continues to be possible because we are still lacking essential commitments from the company," leaders of Volkswagen's (VW) works council said in a letter distributed to German staff on Thursday.

Labour bosses at Europe's largest carmaker want management to agree to fixed targets and quotas for products, output and investment as the two sides wrestle over a turnaround plan for the core VW brand.

Talks between labour and management over the so-called future pact will resume later on Thursday, after leaders have briefed workers at a staff gathering in Wolfsburg.

(Reporting by Andreas Cremer; Editing by Maria Sheahan)