The one-off jump in spending is needed to finance a $1.26 billion deal to purchase eight F-16 aircraft from the United States this year.

Finance Minister Vladislav Goranov said the positive economic outlook and tax collection year-to-date would allow Sofia to make the payment without putting the country's finances at risk.

The head of the budget commission in parliament, Menda Stoyanova, said she expected Bulgaria to end the year with a deficit below 2pc of GDP, given robust economic development.