Labor's fifth straight election win in the ACT could end up being one term too many, Liberal senator Zed Seselja believes.
Chief Minister Andrew Barr claimed victory on Saturday night after the Liberal vote in the territory went backwards.
While the final make up is not yet known, Labor is on track to hold 11 or 12 seats in the 25-seat Legislative Assembly, meaning it can govern with support from the Greens.
But Senator Seselja, who led the Liberal opposition to two ACT elections before entering federal parliament, says what Labor promised during the election is undeliverable.
"They effectively said to people you can have a multibillion dollar new tram but also they were promising to outspend the Liberals in health and outspend them in education," he told Sky News on Sunday.
"When you promise the world in order to get there, it does often come back to bite you and I think this will be the one term too many for the Labor-Greens coalition here in Canberra."
Nevertheless, he said the Liberals would have to examine why they didn't get the kind of swings needed.
Federal Labor leader Bill Shorten congratulated Mr Barr and his team, saying Canberrans voted for a positive, long-term vision for their city.
"Canberrans sent a message to (Prime Minister Malcolm) Turnbull that they did not want another Liberal voice at the COAG table helping Mr Turnbull make more cuts to our schools and hospitals," he said in a statement.
Mr Turnbull took to Twitter to congratulate Canberra Liberals leader Jeremy Hanson and his team on on "a hard fought campaign".
The Liberals went backwards on their 2012 performance, recording a 3.3 per cent swing against them, while Labor's vote improved marginally, up 0.2 per cent.
Labor won 39 per cent of the primary vote, with the Liberals on 35.6 per cent and the Greens 10.6 per cent.
Both major parties are on track to win at least 10 seats in the 25-seat Legislative Assembly.
