The zloty weakened slightly as parliament moved forward with work on a Supreme Court bill that critics say would politicise the judiciary in Poland, central and eastern Europe's largest economy.
"The market might be beginning to speculate on a Czech National Bank hike already next month," a Prague-based dealer said.
The crown was up 0.3 percent by 1001 GMT to 26.03 to the euro. The currency has gained nearly 4 percent since the Czech central bank lifted a cap on the crown in March.
On Wednesday, Bank of America Merrill Lynch brought forward its first expected Czech rate hike to Aug. 3, saying it forecast a hike every quarter from then until the rate reaches 1.0 percent in 2018 from 0.05 percent currently.
"Markets continue to underprice the CNB's near-term tightening prospects," Bank of America Merrill Lynch said. "It is a close call on timing, but it is just a matter of months for the hikes to come, in our view."
The Polish zloty eased 0.2 percent to 4.2075 versus the euro, but stayed close to a 4-week high hit on Wednesday.
Dealers said opposition protests against a planned overhaul of the constitutional court by the ruling Law and Justice (PiS) party had so far had little effect on Polish assets.
Poland's lower house voted on Wednesday to send the contested Supreme Court reform bill to a parliamentary committee. If passed, the bill would give parliament power to indirectly appoint Supreme Court judges, which the opposition says would politicise the judiciary and violate the constitution.
The European Commission, the EU's executive, is due to discuss the Polish judicial bills in Brussels on Wednesday, having expressed concerns for months about the direction of reforms in Poland.
"It seems to me that unless rating agencies start writing and clearly warning about the situation, little will change (with respect to Polish markets)," a Warsaw-based dealer said.
"We have political turbulence in nearly all countries now. Investors are looking more at the macroeconomic situation, and this is relatively good in Poland," the dealer said.
Poland's large-capitalisation stock market index WIG20 gained 0.5 percent on Wednesday ahead of retail sales and industrial output data due to be released by the statistics office at 1200 GMT.
Elsewhere, Hungary's state debt agency confirmed on Wednesday that it had mandated Bank of China and HSBC to organise the issue of a so called "Panda" bond primarily for Chinese institutional investors.