The leverage is applied to the money.
Say a stock is Β£100 to buy normally. If the leverage ratio is 1:5, then by spending Β£20, you can effectively purchase a stock worth Β£100. Likewise, if the margin is dropped to 1:2, to purchase that same stock, you would now have to pay Β£50.
Itβs not related to how many you buy, but the amount of money spent on acquiring those stocks.
So you have purchased 5 shares, your P/L will be representative of owning those 5 shares. If you want 25, you need to buy 25 shares.