OTTAWA -- A preliminary analysis of the federal books says the government ran a budgetary surplus of $300 million through the first nine months of the fiscal year.

The surplus is an improvement compared with the April-to-December period in 2017-18, when Ottawa posted a deficit of $8.9 billion, according to Friday's release of the Finance Department's monthly fiscal monitor.

The document said overall revenues were up $19.3 billion, or 8.7 per cent, compared with the same period last year, due in large part to higher revenues from taxes and incoming employment insurance premiums.

Program expenses were up $8.4 billion, or 3.9 per cent, compared with the same nine-month stretch last year, because of increases in major transfers to individuals, to other levels of government and due to an increase in direct program spending.

The fiscal monitor also said public debt charges rose $1.7 billion, or 10.3 per cent, mostly due to the higher effective interest rate on government debt and the higher inflation adjustments.

For the month of December alone, the government posted a surplus of $2.5 billion thanks to a revenue increase of $2.6 billion. In December 2017, Ottawa ran a $500-million surplus.

The Liberals' fall fiscal update, released in November, predicted the government was on track to run annual shortfalls of $18.1 billion in 2018-19, $19.6 billion in 2019-20 and $18.1 billion in 2020-21.

Finance Minister Bill Morneau was asked Friday by reporters whether the improvement shown in the fiscal monitor would translate into smaller deficits.

Morneau, who will introduce updated fiscal projections in his March 19 federal budget, sidestepped the question and said the economy is doing well. He insisted the stronger bottom line is a result of government investments.

"That said, what you saw this morning was one month's snapshot," Morneau said in Toronto.

"And in order to look at the results you have to look at the entire year. We continue to see this year going well, but we will be prudent and cautious in the way that we manage the economy."

Canadians should expect to hear a lot more about the state of the federal books in the leadup to the October election.

The Liberals have faced criticism from the opposition Conservatives and some economists for failing to provide a timeline to balance the budget. There are warnings the government could face big fiscal challenges when the next economic downturn arrives.

After the 2015 election, the Trudeau government abandoned campaign vows to run yearly shortfalls of no more than $10 billion and to balance the books by 2019. Instead, it has focused on reducing the net debt-to-GDP ratio -- a measure of how burdensome the national debt is -- each year.

The government argues the extra spending, in areas such as infrastructure, has been necessary to help lift Canada's long-term growth.