China's yuan was little changed Tuesday, helped by a steady midpoint fixing and supportive policies, but analysts say downside pressures are building amid a rise in COVID cases and delays over the release of its gross domestic product (GDP) data that have stoked fears of economic weakness.

The onshore yuan was changing hands at 7.1950 at midday, on a par with the previous late session close. Prior to market open, the People's Bank of China set the midpoint rate at 7.1086 per dollar, a level that barely changed over the past week.

The steady fixing is designed to anchor the yuan ahead of, and during the week-long Communist Party Congress that opened on Sunday, analysts said.

In addition, China's state banks stepped up their intervention to defend a weakening yuan, banking sources told Reuters Monday. The yuan's steadiness comes as little surprise to market watchers as Beijing rolls out coordinated and wide-ranging efforts to tamp down ripples of turmoil across financial markets during the twice-a-decade party congress, which marks a politically sensitive time.

But some fear that after the congress is over, the yuan could resume its slide against the dollar, which will likely strengthen further on the back of higher U.S. interest rates.

That concern is compounded by China's delay of key economic data, including hotly-anticipated third-quarter GDP numbers. No date for a rescheduled release has been given.

"The sudden delay of the 3Q GDP spurred rumors that the September activity data is likely to indicate the economic costs of the lockdowns that have been ramped up to suppress COVID outbreaks ahead of the Party Congress," Maybank wrote in a note. "Depreciation pressure could build more significantly on the yuan if USD continues to strengthen broadly."

Traders will also closely monitor China's monthly foreign exchange purchase and settlement data. China's first-half national financial accounts showed that cash is leaving China's financial markets at the fastest clip in years as investors flee a falling currency and sputtering economy.

China's third-quarter GDP is expected to grow 3.3% year-on-year, but "we note significant downside risks to the consensus forecast, owing to a rise in COVID cases" ahead of the Party Congress, UBP SA wrote in a note to clients.