Business is brisk at Hungary’s biggest holiday booking website. Gergely Szugyi, who manages an investment stake in szallas.hu, says the rate of bookings has doubled in the past six months, underlining the improved consumer sentiment that helped propel the central European economy to grow faster than almost every other EU peer in 2014.

After enduring many lean years since the financial crisis no one is more surprised at the uptick than Mr Szugyi.

“Hungarians felt they couldn’t spend anything for the last six or seven years,” he says. “But now they know what their mortgage will cost and their bills are a little lower, so they’ve started to spend a bit more.”For the government it is a resounding vindication of the unorthodox tax measures employed by Viktor Orban, prime minister, to bring order to chaotic public finances while maintaining his party’s dominance.

Many commentators and political opponents predicted “Orbanomics” would lead to economic disaster. Instead, they have found themselves caught off guard by Hungary’s unexpectedly robust growth.

Unbowed, critics are now warning that the pace of growth is unsustainable and accuse Mr Orban of imposing discriminatory taxes on foreign investors and damaging market confidence.

“The economic performance in recent quarters has been achieved in spite of government decisions and not because of them,” says György Surányi, a former governor of the central bank.

Mr Orban returned to power in 2010, inheriting a spiralling deficit and a €20bn International Monetary Fund bailout programme. His government reshaped the country’s taxation system; introducing a flat-rate 16 per cent income tax on one hand, while imposing crisis taxes on telecom, energy, media and financial sectors on the other.

The government also nationalised compulsory private pension funds, opening up a public revenue stream that has reduced the deficit but increased the government’s liabilities by more than 15 per cent of national output, by some estimates.

In 2013, Hungary took advantage of lower borrowing costs to pay-off its IMF loans ahead of schedule and the central bank instructed the Washington-based fund to close its Budapest office.

Despite these complaints, the economy expanded by 3.5 per cent in the first quarter of 2015, compared with the same period last year, thanks to a 2.6 per cent rebound in household consumption, a rise in manufacturing output and billions of euros worth of EU-funded public investments. Public debt has been reduced to 77 per cent of GDP and the government has reduced the deficit to below an EU-mandated target of 3 per cent of output.

Since then, Mr Orban has forced utilities to cut household bills and lossmaking banks to pay €3bn in compensation to bank customers who took out foreign currency mortgages. Such populist measures helped his Fidesz party win another term in office in 2014.

Mr Orban’s taxation measures have provoked accusations of discrimination against foreign investors from the European Commission. The government has since bowed to international pressure and signalled reforms to contentious taxes on media and banks. But foreign investors continue to complain of unfair discrimination in retail and other sectors.

“The numbers indicate a consistently robust recovery,” says Gabor Orban, state secretary for the economy. “This should ease the concerns of some critics that didn’t consider Hungary’s economic policy the right one.”

In May, during a televised speech, Mr Orban told viewers that despite “rampantly aggressive attacks” against his government many foreigners who criticised his policies were now studying the recipe for Hungary’s success.

But his opponents argue that the spectre of struggling banks, unpredictable regulation and an outsized state role in the economy mean the winning streak won’t last.

“The bottom line is the 3.6 per cent we’ve seen is not sustainable and much of it was achieved because as you come out of recession, you get a strong rebound,” said Jorg Decressin, deputy director of the IMF’s European department, last month in Brussels. “This will have to be increasingly funded by the banking sector.”

“Private investment is being held back because of a lack of confidence and the unpredictability of policy making,” says Mr Surányi, who added that Hungary’s growth is mainly fuelled by external factors, like the influx of EU funds and rising real wages due to the fall in global oil prices.

“The so-called ‘crisis taxes’ have been embedded in the system and this undermines the country’s potential for moving to faster growth in the medium term.”

Both sides acknowledge the rate of economic expansion will reduce. In April, the IMF forecast economic growth would slow to 2.7 per cent in 2015 and 2.3 per cent in 2016. It urged the government to support lending by easing the burden on banks.

Officials acknowledge that if the 2010 crisis taxes on the country’s banks aren’t eased, lending will remain sluggish and investment levels will stagnate as the EU funding bonanza comes to an end.

Mr Decressin welcomed recent promises by the Orban government to step away from “intermediation” in the banking sector but warned that such commitments must be kept.

He says: “Otherwise, it will be a mediocre recovery.”