FILE PHOTO: People shop on Oxford Street in London, Britain April 10, 2023. REUTERS/Anna Gordon/File Photo

LONDON (Reuters) -British retailers reported a 12th straight month of falling sales in September and they expect another decline in October as weaker consumer demand and concerns about the government's next budget weigh, a survey showed on Thursday.

The Confederation of British Industry's monthly gauge of how retail sales compared with a year earlier fell to -29 in September from -32 in August.

The CBI's gauge of expected sales for October fell sharply to -36 from -16, the lowest since July.

"Weak demand continues to weigh on sales, while US tariffs are adding pressure for some retailers. Lacklustre economic conditions are also affecting the wider distribution sector," CBI principal economist Martin Sartorius said.

"As we approach the autumn budget, retailers and other distribution firms will want the Chancellor to deliver certainty and restore confidence to businesses and consumers alike."

Sartorius said April's increase in social security contributions for employers and the rise in the minimum wage, also ordered by finance minister Rachel Reeves in her first budget, were continuing to hit the sector.

Retailers and other businesses are concerned about possible further tax rises in Reeves' November 26 budget.

Official data last week showed stronger-than-expected retail sales in August. But consumer confidence weakened this month as concerns about the economy mounted.

(Reporting by Suban AbdullaEditing by William Schomberg)