LONDON - Britain cannot tell businesses to prepare at the last minute if talks between London and Brussels fail to agree a Brexit deal so Prime Minister Boris Johnson will need to make a decision sooner rather than later, a junior minister said on Thursday.

"If we can't get a deal, rightly so, we've got to allow businesses to prepare," junior business minister Nadhim Zahawi told Sky News.

"I can't go to businesses at the 11th hour on the 31st of December... We have to make a decision much sooner."

Goldman Sachs said on Thursday that there could be drama at the EU summit over Brexit but that a thin trade deal was likely to struck by early November.

"Neither the UK Prime Minister's 15 October deadline nor the European Commission's 31 October deadline constitutes a hard stop on Brexit negotiations," Goldman analyst Sven Jari Stehn said in a note to clients. "This week's European Council may well feature an additional dose of political drama."

"We think the perceived probability of 'no deal' will persist through the course of October. But our core view remains that a 'thin' zero-tariff/zero-quota trade agreement will likely be struck by early November," Goldman said.

(Reporting by Guy Faulconbridge; writing by Costas Pitas; editing by Sarah Young and Paul Sandle) ((Costas.Pitas@thomsonreuters.com; 02075428024; Reuters Messaging: costas.pitas.thomsonreuters@reuters.net and @Cpitas on Twitter))