Over the past few weeks, China's Ministry of Finance (MoF) has been teasing markets with the idea of a big fiscal stimulation package about to be unleashed on the spluttering economy.

There have been a few weekend media conferences, promises of a few billion yuan here and there, but in reality, the MoF doesn't have the authority to pull out the fiscal bazooka loaded with trillions of yuan.

The Standing Committee of the National People's Congress does have that authority and is meeting this week.

Expectations after Friday's wrap up are we will see some concrete and sizable stimulus measures tabled.

Societe Generale's China economists are forecasting an immediate package of 3-to-4 trillion yuan ($640 billion to $850 billion).

"We expect the package to commit to a fiscal top-up worth 2.5-3.5% of GDP per annum for the next 3- 4 years, pointing to a reasonable chance of pausing the deflationary spiral," the SG team wrote to clients over the weekend.

"The meeting may also offer forward guidance on further fiscal expansion in 2025, particularly if Trump wins the election.

"We think (Friday's) announcement will be just one of several steps to address China's structural challenges, while a plan to support consumption in the long run is likely to emerge late."

SG argues a 3-to-4-trillion yuan package spread over a couple of years would have a decent chance of accomplishing the urgent task of stopping the deflationary spiral and stabilising confidence.

"Looking ahead, as the policy shift is now clear, we think (the) package will be just one of several steps to address China's structural challenges.

"A plan to support consumption in the long run is unlikely any time soon, so we keep our expectations low on this front for now."

ANZ's China team of Raymond Yeung and Zaoping Xing have slightly different expectations.

They forecast a more modest direct stimulus of1-trillion yuan ($200 billion) via special local government bonds which they argue is enough in the short term to support Chinese GDP to its 5% target.

Yeung and Xing argue the centrepiece will be a 10 trillion ($2 trillion) debt swap program, but "the economic impact will be indirect and unnoticeable".

On ANZ estimates, China's "hidden" debts stand at around 10-to-15 trillion yuan.

Using 10 trillion in new bond issuance to swap for existing troubled debt should in theory enhance credit worthiness of local government by parking the hidden liabilities in the MoF.

"The CNY10trn debt swap plan is meant to relax the financial constrains facing the local governments.

"By reducing their debt burden and interest expenses, they can allocate more financial resources to economic development.

"But the growth impact will not be very visible."

ANZ says the efficacy of the stimulus package comes this an important caveat.

"Growth requires wholesale reform of the fiscal and tax system to support the financial sustainability of local governments," the ANZ team said.