There are many variables that play into the impact that increased government spending will have on price stability. However, one impact that might result from excessive government spending is inflation.
If the government spends too much money (especially when it finances this spending by borrowing), inflation can occur. This could happen for two reasons. First of all, aggregate demand could go up with increased government spending. People will have more money to spend, which will tend to drive price levels up. Second, if government borrowing "crowds out" private borrowing, less investment will happen in the private sector. This can suppress aggregate supply. A decrease in aggregate supply can also cause prices to increase.
Overall, then, excessive government spending is likely to lead to inflation.