Jaroslaw Kaczynski's omission from the official government line up is an “experiment” that will be assessed towards end of the year, the chairman of Poland’s ruling party Law and Justice (PiS) said in comments published on April 18.

Kaczynski is widely considered to be Poland's most powerful man, while officially being no more than a backbench MP. However, his comments suggest he could repeat his trick from PiS' last stint in office to step into the hotseat just months after pledging he would not seek the prime minister's office and instead installing a frontman.

A divisive figure, Kaczynski promised in the successful election campaign last year that he would not seek to lead the country, putting forward Beata Szydlo as PM. Earlier in the year he had put forward Andrzej Duda as presidential candidate.

However, despite a rapid push to consolidate power, the chairman appears unhappy with progress. The Szydlo government is an experiment that will be assessed at the end of the year, he said in comments to PiS-friendly weekly wSieci, demanding the cabinet accelerates the changes being made in the country.

“There are successes but there is nothing worse than us becoming complacent," Kaczynski told the weekly. "Let me be clear: we must move forward, accelerate, start new projects, we just have to move forward even faster.”

The changes in Poland have been coming thick and fast already, many to the disappointment of the international community. Poland is subject to a European Commission probe into the state of the rule of law following the paralysis of the country's Constitutional Tribunal. PiS has also been criticised for its efforts to take control of media and for loosening fiscal policy.

However, several significant campaign pledges remain unfulfilled - including an increase in the income threshold and lowering the retirement age - as the government seeks the cash to drive them via new taxes on banks and retailers. The administration is also trying to thrash out a scheme to allow borrowers to convert Swiss franc mortgages. Other large reforms, such as of education, are also looming.

Should Kaczynski decide the "experiment" has failed and he must move into the driving seat, it would only prove the pundits correct. That said, they had the PiS chairman's own playbook to follow. During PiS’ first stint in power in 2005-2007, Kazimierz Marcinkiewicz spent nearly nine months as a prime minister before Kaczynski decided he was needed in the post.