No, Jonny it is not corruption, it is a case(s) of lobbying (by the PL) and these are the facts.
Lobbying is described by Wikipedia as, " .... a form of advocacy, which lawfully attempts to directly influence legislators or government officials, such as regulatory agencies or judiciary".
The gifts in question have been declared by the MPs in accordance with Parliamentary regulations; therefore nothing untoward has occurred, unless you can either prove that the PL are employing illegal 'lobbying' practices and/or, that the presence (or absence) of these gifts and donations have directly caused these MPs to have changed their minds.