* Graphic: World FX rates in 2019 tmsnrt.rs/2egbfVh
* Graphic: Trade-weighted sterling since Brexit vote tmsnrt.rs/2hwV9Hv
LONDON, Nov 20(Reuters) - Sterling was slightly weaker against the dollar and largely flat versus the euro on Wednesday, showing little immediate reaction to a debate between the leaders of Britain’s two main political parties ahead of next month’s election.
Prime Minister Boris Johnson doubled down on his Brexit promises late on Tuesday, saying only he could take Britain out of the European Union quickly in a testy leadership debate with opposition Labour’s Jeremy Corbyn.
“The debate was not a game changer for sterling,” said Piotr Matys, a currency strategist at Rabobank in London.
“The market reaction would have been stronger if Jeremy Corbyn had gained an advantage in the polls but that doesn’t appear to have been the case,” he added.
In early European trade, the pound was 0.15% weaker on the day at $1.2902 with the U.S. currency broadly benefiting from general risk aversion in world markets on concern over the direction of U.S./China trade talks.
Against the euro, the pound traded at 85.70 pence , off six-month highs hit on Monday at 85.22 pence.
Expectations that the ruling Conservative Party will win a Dec. 12 general election have supported the British currency and analysts said only a significant shift in opinion polls would push the pound out of recent ranges.
If the Conservatives win a majority on Dec. 12, expectations are the House of Commons would approve the Brexit deal agreed with Brussels last month and Britain would exit the European Union on Jan. 31, ending 3-1/2 years of uncertainty for the time being. (Reporting by Dhara Ranasinghe; Editing by Catherine Evans)