Will doing Masters degree help me get into another masters degree? My first degree was in Economics and Finance.  Frankly, I didn't do very well, although I did do enough to scrape a 2:1.  There were a number of legitimate reasons for this underperformance, but it's still a fact.  

Anyway,that was ten years ago.  I am wondering whether studying a masters in one subject will bolster my chances of being accepted to a prestigious masters programme.  E.g. if I study, say, an Msc in statistics at a lower-Russell Group uni now, would that bolster my chances of subsequently being accepted to a top sociology or poli sci programne at a top school? Or would it not make any difference?
Presumably a higher relevant qualification ---or an equivalent qualification that is more recent and with better performance--- will be more valuable than an older qualification with poorer performance.  Additionally, having a Masters degree in statistics (hopefully with good performance) would be of relevant value to entry into sociology or political science.  As to whether it is necessary, who can say.  Perhaps the best option is to apply to both ---i.e., apply to the top schools for immediate entry, and also apply to the MSc in Statistics as a fall-back.  If you are not accepted for the former, you can still do the latter and then re-apply more strongly later.