A party statement referred to a specially arranged EU summit and said several other speakers from around Europe, including industry figures, had agreed to attend the session on September 12 on "minimum Unit Pricing: unintended consequences for the EU and external trade".

Scots Tory deputy leader Jackson Carlaw, who challenged ministers to attend, said: "If minimum unit pricing is not consistent with our obligations and agreements, we need to know now so the Scottish Parliament can urgently identify alternative approaches to tackling Scotland's unhealthy relationship with alcohol."

Mr Stevenson said: "It is not an attempt to hijack the legislation, but there is no point in forging ahead with this only for it to fall at the first legal hurdle.

"Many EU states are concerned at the negative impact it may have and it may be that some of them mount their own legal challenges to test out the merits of minimum pricing."

The Scottish Government said no decision had been made on the invitation but ministers were confident that the legislation complied with EU law on the basis of public health.