* Says May seeks "hard" exit from EU against Scot interests
* Accuses British PM of "constitutional vandalism"
* May to consult with Scots during Brexit process -official (Adds context, details)
By Elisabeth O'Leary
GLASGOW, Oct 13 (Reuters) - Scottish First Minister Nicola Sturgeon raised the prospect of a second independence referendum by 2019, accusing the British government of ignoring Scotland's interests by pursuing a "hard" exit from the European Union.
Speaking at the start of her Scottish National Party's (SNP) bi-annual conference on Thursday, Sturgeon said her devolved government would publish a draft independence referendum bill as early as next week.
Questions about the future of the 309-year union between England, where a majority voted to leave the EU, and Scotland, where a majority voted to stay in it, have multiplied since the June 23 referendum put the entire United Kingdom on the path to an exit.
British Prime Minister Theresa May last week set out the exit timetable by promising to launch the two-year legal process by the end of March, and later triggered a fall in the value of the pound to a 31-year low by appearing to prioritise immigration controls over Britain's current preferential access to the EU single market, which could hurt trade and investment.
"If you think for one single second that I'm not serious about doing what it takes to protect Scotland's interests, then think again," Sturgeon said in a warning to May.
She accused May's Conservative government of "constitutional vandalism" by what she said was its disregard of Scotland's views on Brexit, arguing that it had no mandate to take Britain out of the EU single market for goods and services.
In response, a spokeswoman for May said the prime minister was "absolutely committed to engaging with the people of Scotland, with understanding their interests and making sure that as we go through the process of negotiating the UK exit we do what is in the interests of the United Kingdom".
May said last week she would be "ambitious" in talks with the other 27 EU members to get what she called the best deal.
Sturgeon said she would seek to ensure that Scotland gets increased powers in any negotiation Britain undertakes to leave, challenging May on her stance that any Brexit deal must be negotiated by her government for the whole of Britain.
But Sturgeon also said she wanted a bill in place to give her the possibility of calling another referendum before Britain formally leaves the EU - now expected by the end of March 2019.
"I am determined that Scotland will have the ability to reconsider the question of independence - and to do so before the UK leaves the EU - if that is necessary to protect our country's interests," she added.
Any binding second independence referendum would probably have to be agreed by the British government in London, which has said it considers the matter was settled at a 2014 vote.
May has also denounced "divisive nationalists" and said there would be no Brexit opt-out available for Scotland, Northern Ireland or Wales. A majority in Northern Ireland voted to stay in the EU, while the "Leave" camp won in Wales.
Sturgeon has often said that Scotland must continue to have independence as an option to safeguard its democratic voice.
Although the public mood in Scotland is one of widespread disenchantment regarding Brexit, opinion polls do not indicate that support for independence has increased since Scots rejected it by a 10 percentage point margin in 2014.
Sturgeon also said she was aware that she was treading a fine line between hardliners who want to split from the UK and those wary of rocking the boat further after the Brexit vote, which has already unsettled Britain's economy.
Her SNP is by far the dominant Scottish party, running the country's devolved government and holding 54 of the 59 designated seats for Scotland in the London parliament.
Sturgeon said her government planned to seek powers to give Scotland a more inclusive and internationalist path.
"We will seek to make this plan a key element of the UK's Article 50 negotiation. It will require substantial additional powers for the Scottish parliament: all the powers in our areas of responsibility that currently lie with the EU - and significant new powers too." (Additional reporting by William James; editing by Stephen Addison and Mark Heinrich)