The Prime Minister "has no mandate" to remove "any part of the UK" from the European single market, the First Minister has said.

Nicola Sturgeon made the remarks in her address to the upper house of the Irish parliament, the Seanad.

Her speech was the first time a serving head of government addressed the body.

Speaker of the house Denis O'Donovan described it as an "historic occasion" which "will deepen and strengthen the links between our two countries".

The First Minister told senators: "Scotland believes the UK as whole should now seek continued membership of the European single market and the European customs union.

"After all, 48% of voters choose to remain in the EU. So too did two of the four nations of the UK.

"And many people who campaigned to leave the European Union were clear in their view that doing so need not involve leaving the single market.

"So I accept there is a mandate for the UK Government to take England and Wales out of the EU but I do not accept there is a mandate to take any part of the UK out of the single market especially when we consider the economic consequences of such a step."

The First Minister said a second independence vote "remains on the table" following June's vote to leave the European Union.

The Scottish Government has previously said a hard Brexit will lead to a fresh referendum on independence.

Sturgeon's government has drafted legislation for a new referendum.

On Friday, Sturgeon held a bilateral meeting with Irish taoiseach Enda Kenny in Cardiff after the pair attended a summit of the British-Irish council.

In the first European Council meeting after the UK voted to leave the EU, Kenny reportedly put forward the Scottish Government's case to remain part of the organisation.

Sturgeon was not able to attend as Scotland is not a member state, it is part of one.

The First Minister said she was "very grateful" for the taoiseach's intervention.

Sturgeon also met the Irish foreign secretary Charlie Flanagan on Monday.

Commenting on her meetings with Flanagan and Kenny, Sturgeon said: "It was clear from both of these discussions that Brexit is the greatest foreign policy challenge of Ireland has faced since it joined the European Union.

"And for Scotland too we know how we, and, indeed, how the UK as a whole responds to June's vote will define us for generations to come".

The First Minister also used her speech to extend her government's support for an open border between Northern Ireland and Ireland after Brexit.

Both governments, and the Northern Irish executive, have expressed their support for no hard border on the island.

Senators gave the First Minister a standing ovation while some also expressed support for Scottish independence and Sturgeon's ambition to retain EU membership.

Senator Catherine Adagh, who leads the second largest party in the Seanad, Fianna Fáil, said the "day will come" when Scotland is independent.

A spokeswoman for the UK Government said: "The United Kingdom voted to leave the European Union and we are committed to securing a deal which works for all parts of the UK, and for the UK as a whole.

"That means securing for British businesses maximum access to, and freedom to operate within, the single market.

"But when it comes to markets, the United Kingdom is Scotland's vital union: our own domestic market is worth four times as much to Scottish businesses as the EU market.

"Our focus should be on working together to secure the best deal for the UK."