A spokesman for the road hauliers’ association, ANTRAM, late on Monday welcomed the possibility of such a move, pledging not to give in to "blackmail" on the part of unions, which have demanded a counterproposal until Friday. That was after unions said that the strike threat would remain in place until Friday, the deadline they had given ANTRAM to submit a concrete proposal to be voted on by its members.

"We welcome this decision by the government and acknowledge that the government has, in fact, made a great effort for the parties to reach agreement," André Matias de Almeida of ANTRAM told Lusa.

His comments came after the National Union of Dangerous Goods Drivers (SNMMP) and the independent Union of Freight Drivers (SIMM) held a meeting in Lisbon with the minister for infrastructure, Pedro Nuno Santos.

“The government has today proposed to the unions to trigger a legal mediation mechanism provided for in the Labour Code, in which the parties are called to negotiate and, if there is no agreement, the Government itself, through the Directorate-General for Employment and Labour Relations, will present a proposal for a collective bargaining agreement, under the law", the Ministry of Infrastructure said in a statement.

According to the government, the mechanism, if accepted by the unions, would allow "the strike to be called off and the parties to resume dialogue and negotiation in a new legal framework".

The indefinite strike, which was called by the SNMMP and SIMM to start next Monday, 12 August, would threaten the supply of fuels and other commodities. A similar stoppage in April saw long queues at petrol stations and major logistical problems.

The government has yet to set legally mandated minimum services for the strike, after the proposals of the unions and ANTRAM diverged drastically – with the former proposing 25% of normal service and the latter 70% - as well as to decide whether the minimums should include supplementary work and loading and unloading operations.