Further rate hikes "will likely come in consecutive months, the MPC will prefer not to take breaks," Kotecki said, adding that the hikes would be "necessary". 

The surprisingly low 75 bp hike in May may translate into a longer tightening cycle or steeper hikes in the future, Kotecki warned. 

"We expected it to be 100 bps in May, but it came out at the level of 75 bps, and that will likely mean that a portion of the hike has not been implemented, and it will likely be shifted to the following months," said Kotecki. 

Poland's MPC hiked its interest rate by 75 bps in May to put the reference rate at 5.25 per cent.