Wellington's mayor is again under fire as a crucial meeting begins to set the capital's budget for the next 10 years

Long Term Plan deliberations are underway, where councillors are considering a 16 percent rates rise for the next year.

It's an important budget for the capital, which is facing cost pressures from aging water pipes, seismic issues, social housing and transport.

But councillors have arrived unimpressed by an email in the early hours of this morning from Andy Foster, proposing a number of last-minute changes.

Diane Calvert has called it alarming, while Jill Day says it's terrible governance.

The mayor attracted similar criticism when he did the same thing before a crucial meeting on the library earlier this year, springing a surprise proposal to sell part of the building at the eleventh hour via email.