WARSAW, April 4 (Reuters) - Poland's government wants to allocate about 2 billion zlotys ($506.87 million) to buy excess grain from its farmers, a deputy agriculture minister said on Thursday, according to PAP news agency.

"We want to allocate approximately 2 billion zlotys to purchasing surplus grain from the market. ... Arrangements with the Ministry of Finance on this matter are currently underway," the minister, Stefan Krajewski, was quoted by PAP as saying.

"The drafts are ready, they must go through their own procedural path, but we want to introduce them as soon as possible," he said, according to PAP. Krajewski said the aim was to pay out the subsidies by the end of May.

Farmers in Poland have blocked motorways and border crossings with Ukraine and infuriated Kyiv by spilling loads of imported grain across train tracks, as they demand the re-imposition of customs duties on agricultural imports from Ukraine that were waived after Russia's invasion in 2022.

They say Ukraine's farmers are flooding Europe with cheap imports that leave them unable to compete and that much of the grain that is supposed to transit through Poland ends up on the domestic market. ($1 = 3.9458 zlotys) (Reporting by Karol Badohal; Editing by Leslie Adler)