* DUP: We cannot support the deal
* Sterling falls
* Blow to Brexit talks before summit
By Guy Faulconbridge and Kate Holton
LONDON, Oct 17 (Reuters) - Northern Ireland’s Democratic Unionist Party said it could not support the last-ditch Brexit deal being proposed by Prime Minister Boris Johnson and the European Union, a serious blow to Johnson just hours before the bloc’s leaders meet at a summit.
Johnson is trying to strike a Brexit deal at the EU summit to allow an orderly Brexit on Oct. 31, though if he fails to get one approved then he is obliged by a law passed by his opponents to ask for a delay.
British and EU negotiators worked through several nights ahead of Thursday’s summit to agree a compromise on the Irish border issue, the most difficult part of Brexit, haggling over everything from customs checks to the thorny issue of consent.
But the Democratic Unionist Party (DUP), which supports Johnson’s government, said it was not acceptable - a step that could spur hardline Brexiteers in his party to also vote against any such deal if he brought it back to the British parliament for ratification.
“As things stand, we could not support what is being suggested on customs and consent issues and there is a lack of clarity on VAT,” DUP leader Arlene Foster and deputy leader Nigel Dodds said in a statement.
“We will continue to work with the Government to try and get a sensible deal that works for Northern Ireland and protects the economic and constitutional integrity of the United Kingdom.”
Just two weeks before the latest deadline for the United Kingdom’s exit, Brexit remains uncertain with options ranging from an orderly departure to a chaotic exit or even another referendum that could reverse the entire endeavour.
A Brexit-supporter who was the face of the campaign to leave in the 2016 EU referendum, Johnson has repeatedly said he will not ask for a delay though his government also says it will obey the law.
Johnson, who has no majority in the 650-seat parliament, needs 320 votes to get a deal ratified. The DUP have 10 votes. The British parliament is due to meet on Saturday in an extraordinary session - the first such meeting since the 1982 Argentine invasion of the Falkland Islands.
Sterling slid as much as 0.6% to $1.2748, and also declined 0.5% versus the euro to as low as 86.81 pence , before steadying and recouping some of those losses. (Reporting by Guy Faulconbridge and Kate Holton; editing by Andrew MacAskill)