LONDON (Reuters) - A senior member of German Chancellor Angela Merkel's party said on Friday he had trouble trusting Greece's latest proposals to its euro zone creditors as the country had last week decisively rejected the austerity measures in a referendum.

The Greek government sent a package of reform proposals to its euro zone creditors on Thursday in a race to win new funds to avert bankruptcy and will seek a parliamentary vote on Friday to endorse immediate actions.

"We have to be very careful because honestly, because I have a little bit of a problem to trust it because what is the difference between Sunday and today? ... on Sunday the Greek people voted against these measurements," Michael Fuchs, deputy parliamentary floor leader of Merkel's Christian Democrats, told BBC Radio in English.

"We need to make sure that the debt sustainability is now served, if that is not functioning it doesn't make sense."

(Reporting by Kylie MacLellan and Li-mei Hoang; editing by Guy Faulconbridge)