A vote to renew Trident against the wishes of nearly every MP in Scotland has sparked further calls for a vote on independence.
In a vote in the House of Commons, 58 of Scotland's 59 MPs voted against Trident renewal - with Scotland's only Tory MP, David Mundell, being the sole supporter.
SNP Westminster leader Angus Robertson said the vote exacerbates the "democratic deficit" in Scotland weeks after Scottish voters overwhelmingly voted in favour of the EU but were outvoted by England and Wales.
Conservative MPs said the SNP has disregarded the 13,000 Scottish jobs unions say are dependent on the Trident fleet at HMNB Clyde.
Meanwhile, four protesters chained themselves to the gates of Holyrood Palace, the Queen's residence in Edinburgh outside the Scottish Parliament.
Malcolm Bruce and David Mackenzie unfurled a banner which read "HMS Trident 2? We say naw!" and chanted "Ban the bomb".
Wheelchair user Mike Blackshaw chained himself to the public entrance gate, and linked arms with Janet Fenton of the Edinburgh Peace and Justice Resource Centre.
First Minister Nicola Sturgeon said she would hold another referendum if it is in the best way to protect Scotland's interests in Europe but has said she will consider other options.