India’s economic growth accelerated to more than 8% in the final three months of last year, beating all forecasts by economists just months before an election.

Gross domestic product rose 8.4% from a year ago, the Statistics Ministry said Thursday, buoyed by strong private-sector investment and a pick-up in services spending. GDP figures for the previous two quarter’s were revised to above 8% as well.

The government now predicts growth will reach 7.6% in the fiscal year through March, higher than an earlier projection of 7.3%, keeping India on track to remain the fastest-expanding major economy in the world. That’s buoyed sentiment in the nation’s stock market and gives Indian Prime Minister Narendra Modi a boost as he contests elections likely to kick off in April.

"The revisions in the recent growth data show India is already an 8% growth economy and accelerating, which sets it apart from the rest of the world,” Rahul Bajoria, an economist with Barclays Bank, said by message. "Investment numbers suggest an ongoing pickup in capex momentum.”

Analysts pointed to a surge in taxes as a possible reason for the unexpected jump in GDP. The ministry’s figures for gross value added — which is GDP excluding taxes and subsidies — showed a slowdown to 6.5% in the fourth quarter from a revised 7.7% in the previous three months.

The wide gap between GDP and GVA "followed from a surge in the growth of net indirect taxes to a six-quarter high 32% in this quarter, which is unlikely to be sustainable,” said Aditi Nayar, an economist with ICRA, said in an email. She added that GVA growth was a more appropriate measure of underlying momentum in the economy.

V Anantha Nageswaran, India’s chief economic adviser, said strong domestic demand and private investments will continue to drive growth. "The Indian economy is ticking many boxes in the right manner,” he told reporters in New Delhi on Thursday.

Relatively strong growth may keep the Reserve Bank of India on guard as it tries to bring inflation down to its 4% target. The central bank has kept interest rates unchanged and stuck to a relatively hawkish policy stance for several months, although some policy committee members argue that keeping borrowing costs too high could stifle economic growth.