The SNP will "never stop twisting the truth and distorting reality" to increase support for independence, the Prime Minister has said.

Theresa May said "facts and logic" are on the side of the case against independence during her speech to the Scottish Conservative party conference in Glasgow on Friday.

May also used her conference address to hint that directives currently set by the European Union, which the Scottish Government must implement in areas such as agriculture, would be set by the UK Government after the country leaves the organisation in spring 2019.

May said: "The fundamental strengths of our union, and the benefits it brings to all of its constituent parts, are clear.

"But we all know that the SNP will never stop twisting the truth and distorting reality in their effort to denigrate our United Kingdom and further their obsession of independence.

"It is their single purpose in political life."

The Prime Minister added: "We need to be equally determined to ensure that the truth about our United Kingdom is heard loudly and clearly.

"As Britain leaves the European Union and we forge a new role for ourselves in the world, the strength and stability of our Union will become even more important.

"We must take this opportunity to bring our United Kingdom closer together."

First Minister Nicola Sturgeon has said a second referendum on independence is "highly likely" following the UK's decision to leave the EU last year.

The Prime Minister pledged to ensure "no decisions currently taken by the Scottish Parliament will be removed" from Holyrood during the Brexit process.

Since 1999, the devolved administration has been responsible for the agriculture, fishing and environmental decision-making.

The European Union is responsible for imposing directives to set common standards across the European single market and the Prime Minister hinted the UK Government could fulfil this role in future.

The Prime Minister said: "The UK devolution settlements were designed in 1998 without any thought of a potential Brexit.

"In areas like agriculture, fisheries, and the environment, the devolution settlements in effect devolved to the legislatures in Edinburgh, Cardiff and Belfast the power to implement EU directives in these areas, within a common EU framework.

She continued: "The essential common standards which underpin the operation of a single market were provided at the European level.

"As we bring powers and control back to the United Kingdom, we must ensure that right powers sit at the right level to ensure our United Kingdom can operate effectively and in the interests of all of its citizens, including people in Scotland.

"We must also ensure that the UK which emerges from the EU is able to strike the best possible trade deals internationally."

May added: "In short, we must avoid any unintended consequences for the coherence and integrity of a devolved United Kingdom as a result of our leaving the EU.

"As I have made clear repeatedly, no decisions currently taken by the Scottish Parliament will be removed from them."

Nicola Sturgeon, in a speech earlier this week, said such a move would be "unacceptable".

SNP deputy leader Angus Robertson accused the Prime Minister of "mind-boggling hypocrisy" over Brexit.

Former SNP leader Alex Salmond said her hint of not fully devolving all agricultural powers was a "power grab" and an "attack" on devolution.

He told the BBC: "What she announced today was a power grab. She's actually proposing that if Brexit goes ahead the powers that should come back to Scotland on fishing, farming and a range other issues - she's going to retain them at Westminster, because she likes the look of the British economic zone.

"That's a fundamental attack on the very principle and foundation in statute of the Scottish Parliament of 1999, which said specifically that anything that wasn't reserved to Westminster should be run in Scotland.

"This is Prime Minister who is attacking the very foundations of the Scottish Parliament and she'll do it to her cost. "