Johnson rocks boat as referendum Bill passed

European union: SNP wrecking amendment fails by majority

David Cameron is facing growing demands to allow ministers to campaign for an EU exit as legislation for a historic referendum cleared its first parliamentary hurdle.

As the Prime Minister prepares for another round of whirlwind diplomacy pushing his renegotiation agenda in Brussels, Boris Johnson insisted dropping collective responsibility in the run-up to the poll would be “safer and more harmonious”.

The intervention by the mayor of London, a member of the Prime Minister’s Cabinet, frustrated Downing Street’s efforts to move on from Monday’s confusion over whether or not Mr Cameron had said he would sack anyone who defied the Government line.

The European Union Referendum Bill passed its second reading in the Commons, by 544 to 53.

An SNP wrecking amendment calling for 16 and 17-year-olds to be allowed to take part and requiring majorities in each of the four UK nations before ‘Brexit’ occurs was also seen off by a majority of 279.

The Bill will now undergo detailed committee stage scrutiny on the floor of the House, starting next week.

Earlier, SNP MP and former First Minister Alex Salmond described the referendum as a “nonsense” and a mere sop tactic to assuage Ukip supporters and backbenchers.

He added it was “deeply insulting” to exclude 16 and 17-year-olds from voting.

Former Conservative minister Ken Clarke said: “If we’re going to demand treaty change to permit us to discriminate against European foreign nationals... perhaps all foreign nationals in our employment laws or our tax system or our benefits system, well are they going to forgo from the same thing against British residents in other countries?”

Pictures: PA. Alex Salmond during his hard-hitting Commons speech and Ken Clarke, who backed the EU.