The Scottish First Minister said she is not seeking endorsement for a second independence referendum at present
Nicola Sturgeon has told the Scottish Parliament she is determined the country's voice "will be heard" after the UK Brexit vote.
Scotland's First Minister is due to travel to Brussels on Wednesday to meet European Parliament President Martin Schulz.
She is seeking cross-party backing from Members of Scottish Parliament (MSPs) to pursue talks aimed at protecting Scotland's place in the EU after 62% of Scots voted to Remain in the bloc.
Speaking during an emergency debate at Holyrood, Ms Sturgeon said: "Scotland spoke clearly for Remain and I am determined that Scotland's voice will be heard."
She told the Parliament she was not seeking endorsement for a second independence referendum at present.
But she would put the option on the table if it emerges as the only or best way to keep Scotland in the EU.
"Based on a very clear result in Scotland, if we were to be removed from the EU, it would be against the will of our people," she said. "That would be democratically unacceptable."
She added: "It is for that reason that I have said that everything must be on the table to protect our place in Europe - including a second independence referendum."
With both the Conservative party and UK Labour in turmoil, Ms Sturgeon - who met with President Michael D Higgins yesterday - said there was a need for "principles, purpose and clarity - in short, for leadership.
"This is why the vacuum that has developed at Westminster is so unacceptable.
"Politicians who proposed this referendum - no matter how bruised they feel by the result - have a duty now to step up and deal with the consequences of its outcome.
"Those who campaigned for a Leave vote - making a number of promises in the process - must now be clear and honest about their plans to deliver."
Ms Sturgeon insisted there cannot be "three months of drift" while both government and opposition parties hold leadership contests.
She announced the establishment of a standing council of experts to provide advice to the Scottish government on how best to "secure Scottish interests and objectives".
Ms Sturgeon was speaking as EU leaders including David Cameron gathered in Brussels for emergency talks on the consequences of the referendum vote.
On his arrival Mr Cameron said he would urge them and EU institutions to take a "constructive" approach to leave negotiations.
Earlier, UKIP leader Nigel Farage mocked MEPs over Britain's decision to leave the EU, telling them: "You're not laughing now."