Health officials are warning that district health board deficits could hit $225 million if nurses accept a proposed deal.

The latest monthly financial update for the 20 DHBs, published by the Health Ministry online today, reveals that they expect to rack up a total combined deficit of $189m this financial year.

For the eight months until February, they had a combined deficit of $73-$27m worse than expected. The forecast year-end deficit was listed at $189m.

All but three DHBs did worse than they budgeted to in the eight months to February.

They were: Southern $4.9m worse than budget; Tairawhiti $3.7m; Bay of Plenty $3.2m; Taranaki $3.2m; Canterbury $2.7m; Waikato $2.2m; MidCentral $2m; Hawke's Bay $1.6m; Hutt Valley $1.4m; Nelson Marlborough $1.2m; Wairarapa $1m; Auckland $596,000; Waitemata $556,000; Northland $552,000; Whanganui $$520,000; West Coast $93,000; and Lakes $43,000.

The ministry said the deficit forecast was largely consistent with information provided to Treasury as part of the Budget Economic Fiscal Update, or BEFU process.

It said average full-time DHB staff numbers were 421 below budget. Of interest amid concern about delayed maintenance and substandard hospital buildings is capital expenditure at $225m dollars in the year to February - $140m below budget.

Wellington's Capital and Coast DHB performed better than it budgeted for last month, to the tune of $1.9m; Counties $454,000; and South Canterbury $354,000.

Fourteen DHBs had annual plans for the 2017-18 year approved by the end of February. Still unapproved were Canterbury; Capital and Coast, Counties Manukau; Southern, Tairawhiti and Waikato.

The Ministry said it believed the deficit would increase to approximately $209m by 30 June.

It went further, however: "In addition, the new nurses MECA [multi-employer employment agreement] settlement proposal could, if accepted, also impact on DHBs' financial results with an additional $16m proposed be incurred in 2017-18.

"Therefore, we have increased our forecast for 2017-18 to a sector deficit of $225m."

Nurses rejected the second proposed pay deal from their DHB employers on 26 March and are now considering whether an independent panel could resolve a pay impasse.

According to DHB data, higher costs for things such as labour, services and clinical supplies are the reason for the $27m blowout in budget expectations over the past 8 months.